DE1057505B - Method and device for monitoring a system for the transmission of mechanical or electrical signals - Google Patents

Description

The invention relates to a method for monitoring a system for the transmission of mechanical or electrical signals by means of a control signal given to the input of the system with a frequency or frequencies not present in the actual signal. The subject of the invention is furthermore a device with which the method according to the invention can be carried out in an expedient manner can.

The purpose of the invention is to provide systems for the transmission of any mechanical or electrical Signals are used continuously and automatically to work correctly during their operation monitor and immediately trigger a display or other process if this monitoring occurs an error or incorrect operation of the system is detected. The invention is based on plants of any kind applicable, with mechanical or electrical signals being mechanical or electrical quantities of any kind are to be understood, which are passed on by the system to be monitored will.

For a long time, efforts have been made to install mechanical or electrical transmission systems during their operation to be constantly monitored in such a way that any error occurs immediately and regardless of the attention of the Operating personnel is determined. The solution to this problem is particularly urgent in such cases where failure of the system could result in an accident. These include, for example the electrical, electronic and mechanical systems in airplanes or other vehicles. Nuclear and nuclear process plants and their controls, including controls for nuclear reactors belong here too. After all, systems for transmission are mechanical or electrical Signals in the sense of the present invention also the control and safety devices on gas, Oil, coal and similar burners.

But also in systems where · a mistake or incorrect work does not have fatal consequences constant and automatic monitoring is very desirable. This includes almost all electrical ones and electronic circuits such as amplifiers, control and servo circuits, receivers, transmitters, communication systems, Calculating machines, recording devices, measuring devices, electronic navigation aids, Echo sounding systems, radars, timers, etc. All of these devices can be operated reliably using the method according to the invention are monitored to ensure that they are working properly.

Many attempts have already been made to achieve a reliable, permanent and automatic Monitoring the facilities to find. One known method of monitoring is exemplary methods and furnishings

for monitoring a system

for the transmission of mechanical

or electrical signals

Applicant:

Scully Signal Company,
Melrose, Mass. (V. St. A.)

Representative: Dipl.-Ing. R. Müller-Börner, patent attorney,
Berlin-Dahlem, Podbielskiallee 68

Claimed priority:
V. St. v. America 19 August 1953

William G. Rowell, Quincy, Mass. (V. St. A.),
has been named as the inventor

be wise to provide two identical systems of the type to be monitored and the outputs of the constantly compares both systems with each other. As soon as one of the systems fails or works incorrectly, this error becomes noticeable when comparing the outputs. By having two identical Must provide systems, this type of monitoring is very expensive and cumbersome and can in addition, do not use it at all for very large and complex systems. Besides, of course it can it can happen that errors occur simultaneously in both systems, so that the comparison of the outputs of the two systems does not always reliably indicate that the work is being carried out correctly.

Other known suggestions for monitoring are primarily for oil burners and their associated ones Control systems determined. By means of individual monitoring relays and similar devices, According to these known proposals, however, only individual parts of the control system are monitored. This type of monitoring is therefore not reliable and, moreover, not immune to interference.

For electronic computing devices that have a very large number of electron tubes and other switching elements contain, one has a monitoring or, more correctly, a verification of the correct way of working tried in such a way that one periodically gives a known task in the computing device and the solution delivered by the computing device

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trolls. However, since there is no task, frequency-sensitive means again from the actual for their solution all switching elements of the signal separate control signal of a device Computing device can be used in this way, which is a display or a process only a limited number of triggers if the control signal is switched off for a period of time of the computing device must be checked. Of course, the longer than the period of the control remains understandable in this way there is also no ongoing signal.

Surveillance, but only an examination as a rule. Of all procedures that have become known so far

moderate intervals possible. the invention differs in that the

Another known method of checking the control signal to be a component of the actual

The way a system works is that one becomes io signal and together with it through the to

A signal monitoring system is briefly running on the input of the system. So as long as the actual

there and the arrival of this signal at the output borrowed signal flawlessly and in the desired

the system checked. Even with this, not all ways can be transferred from the system, this also occurs

Switching elements or other parts of an over- control signal at the output of the system in the front

transmission system must be checked. Furthermore, the 15 given way can be.

Check only periodically at certain intervals - For the essence of the invention, it is irrelevant

lead, the actual working of the plant modulating what form the actual signal

must be interrupted. This type of test has got control signal. For example, the control

also has the disadvantage that the system does not signal from a periodic interruption of the

exist under the same conditions and with the same 20 actual signal. Any other kind of too

Signal is checked, but the control signal, which otherwise modulates the system normally, is also for

wisely transferred. basically suitable for the purposes of the invention.

Now the monitoring line status is also used for monitoring a line been proposed, in addition to the th system is a device that is connected to the signal to be transmitted a special 25 gear of the system to be monitored To give control signal to the system and this and in a certain way to the control signal to control signal to be used for level regulation. speaks. As long as the control signal is in compliance with the regulations has the control-like type serving for level regulation arrives at the exit of the system and a frequency that is in the spectrum of the signal reached by the device becomes an indicator or signal transmitted actual signal occurs. Event not triggered at 30. Only when the control of this known method is but a complete signal for a time that is greater than that and reliable monitoring of a transmission period of the control signal, speaks system not yet possible because the actual signal device is on and triggers a display or a and the control signal is based at least partially on two other processes. So the device must separate channels are transmitted, so that even 35 can be time-sensitive and distinguish whether if the control signal is correctly transmitted, a period of time is shorter or longer than that not the proper transmission of the actual period of the control signal. To this end Signal is guaranteed, while vice versa this can be given to the device a delay, Control signal can fail, the system itself is about the same as the period of the control signal. borrowed signal but transmits properly. 40 As a result of this delay, the device remains that way for example in the important case for which the long is excited by the control signal, such as this one Invention is particularly apt to occur when its receipt. The delay of the device actual signal a direct current signal, the control prevents the excitation within the period signal but is an AC signal. A malfunction of the control signal stops. Only after one in the direct current coupling within the time to be exceeded, which is greater than the period duration of the control monitor The system does not need a signal at all, the excitation of the device stops, the transmission of alternating currents is detrimental to if not affecting a new control signal in the device. Since this well-known proposal is what counts.

actual signal to be transmitted, on the one hand, and the particularly advantageous feature of the invention

Control signal, on the other hand, carry out completely or partially independent procedures if one uses the

depending on one another due to the on-modulation of the actual signal to be monitored

location is a reliable monitoring control signal automatically through the to

this is not necessarily guaranteed. monitoring system can arise itself. To this

The invention, however, proposes a way to achieve a further feature of the purpose a constant and independent monitoring of a 55 invention proceed in such a way that at the exit of the plant for the transfer of mechanical or electronic systems to the mechanical or tric signals by means of a device in front of the system that responds to the input of the electrical signals given control signal with a not seen in, which in turn is a control signal for as long the actual signal present or generated when it arrives at the output of the system, To carry out frequencies in such a reliable manner, 60 and that with this control signal the transmitted that a failure or some other undesirable mechanical or electrical signal modulates change of the actual signal to be transmitted.

always and inevitably a corresponding failure. In the simplest case, this can occur at the output of the

or a corresponding change in the control signal to be monitored system provided device

has the consequence, so that on the basis of the control 65, in the cycle of the control signal between two feeds

signals be the state of the system continuously and states of the relay toggling back and forth, the at

can be monitored negligently. Arrival of the actual signal is triggered

The method according to the invention consists in maintaining its periodic tilting movement as long as

that the actual signal leads with the control signal, like a signal at the output of the system

modulatable and that comes through 70 at the exit of the system. The relay operates a switch that is in the

Input of the system is arranged and the actual signal to be transmitted before reaching the The input of the system is periodically interrupted or chopped up in the cycle of the back and forth tilting relay.

The control signal can also be generated by an independent modulation device and modulate the source of the actual signal to be transmitted.

The invention can be used with advantage in so-called flame monitors, where the actual, of The signal to be transmitted to the flame monitor, either directly or indirectly, from the signal to be monitored Flame of the burner is generated. Most of the time it will be a DC electrical signal act, that of a photocell that picks up the radiation from the flame or of a Probe electrode, which protrudes into the space of the flame, is supplied. Such forms of application of the invention are described later with reference to the drawing.

The invention can be further developed and improved through numerous modifications and additions. Such possibilities are explained below with reference to the drawing.

Further details and possible embodiments of the invention can be found in the description of FIG Examples shown in the drawing. It shows

Fig. 1 is a block diagram to explain the operation of the invention,

2 is a schematic circuit diagram of an embodiment of a device operating according to the invention,

FIGS. 3, 4 and 5 are similar schematic circuit diagrams of modified devices;

6 shows a similar circuit diagram of an embodiment of the invention for pilot flame burner monitoring,

7 shows a similar circuit diagram of the device according to the invention for a photocell control,

8 and 9 modifications of the device according to FIG. 7,

Fig. 10 is a circuit diagram of another modified device that operates with a control signal relative high frequency works,

11 and 12 circuit diagrams of a further embodiment of the invention,

Fig. 13 is a circuit diagram of a device which not only the signal transmission itself, but also the Excitation of a process or a signal in the event of a fault in the system to be monitored the triggering device is monitored,

Figure 14 is a view, partly in section, of mechanical equipment embodying the method of the invention applies,

FIG. 15 shows a modification of part of the system of FIG. 14,

16 is a schematic diagram of a modified monitoring device and FIG

Figure 17 is a schematic circuit diagram of another modification of the invention suitable for use is set up with a sound amplifier system.

Because the method of the present invention can be used in various electrical, electronic, mechanical and electromechanical systems and is completely independent of the system to be monitored, the invention will first be explained using the general block diagram of FIG. This block diagram represents any system 1 in which a signal from source 3 from input 5 of system 1 to its output? should be transferred. The term "signal" is used here in a very broad sense and is intended to mean any message, thing, substance or energy and the like that flows from the entrance of the system through the system to the exit. The invention makes it possible to continuously monitor the correct operation of the system while the signal is being transmitted by the same. This is brought about by a modulation device 9 which generates a control signal with a more or less constant frequency and is connected to the input 5 of the system 1 by a switch S in its position A. This modulation device 9 modulates the signal that comes from the signal source 3 to the input 5 with the control signal. If desired, the modulation can be carried out directly at the signal source 3 if the switch "S" is kept permanently in position B. In any case, the modulation device 9 modulates the signal at the input 5 with the control signal.

The modulation device 9 must modulate the signal so that the modulated signal by the parameters the transmission system 1 goes through. The modulation is then used as a control signal at output 7 recovered, the output 7 containing a device which separates the control signal. It can therefore the control signal only goes through the system if the main signal is also transmitted through it will. The output circuit of the system must be tuned to the frequency of the control signal so the actual signal is suppressed and the control signal is filtered out. Because the control signal is not can appear at output 7 if the actual signal from signal source 3 does not pass through the plant has been transmitted to output 7, the presence of the control signal at output 7 is the correct one Work on the signal source 3 and the transmission system 1.

A display should now be triggered automatically if system i is not working properly. A very brief absence of the signal or a brief undesired response of the system 1 should be clearly distinguished from a real failure of the source3 and the system. The output 7 therefore cooperates with a controller 11 for the device 13 which causes or effects the display and which has a delay of a predetermined time T. If the control signal does not appear at output 7 for a period of at least T, then and only then should an automatic display be triggered. In the schematic representation of FIG. 1, this display is brought about by a controller 11 of the device 13, for example by energizing or de-energizing the same.

The period duration of the control signal must be shorter than the predetermined time period T, since otherwise the device 13 would respond in an undesirable manner within a period of the control signal. It can be useful that the modulation device 9 is controlled by a type of feedback from the output 7, which should be indicated generally by the dotted line.

In Fig. 2 is a specific example of a plant using the monitoring method of the invention, shown. Any type of electrical or electronic transmission system is denoted schematically with 1. Plant 1 can be a

electrical network or any other transmission device be e.g. B. an amplifier system according to FIG. 5 or an electron tube control system according to FIG. 6 or a radiation receiving system according to FIG. 7 or a radiation modulating system according to FIG. 8 etc. In this context it should be noted that only for the purpose of better explanation each one certain circuit or other details contained therein in connection with a single Figure will be described as all circuits and details are just as well in all other figures could be included.

Any electrical signal is fed from the signal source 3 to the input 5 of the transmission system 1, via a line 15 and via lines 17 and 19, which are connected to one another when a switch in the manner shown 21 touches a contact 23. However, if the switch 21 is pivoted down and the contact 23 is interrupted, the lines 17 and 19 are separated from each other, and the main signal from the Source 3 is blocked from input 5. A periodic oscillation of the switch 21 therefore modulates the electrical signal by periodic chopping at the input of the system 1. The switch 21 and the Contacts 23 belong to the modulation device 9 of FIG. 1.

Since the control signal cannot be present if the electrical signal from source 3 is not present is, it cannot occur in the absence of the actual signal in output 7. The modulation by closing and opening the contact 21, 23 is equal to the size of the actual signal, so that it goes through the parameters of the system 1, as this affects the transmission of the actual signal are turned off.

At the output 7 a device is connected, which consists of a relay coil 25, whose Armature 27 controls switch 21. The relay coil 25 is connected to a capacitor 29 in parallel.

If the relay 25 is normally in the position shown in the de-energized state, so when the actual signal is applied to input 5, provided that the system 1 is correct works, the relay 25 energized. When the relay 25 is energized, the armature 27 moves downward, with the switch 21 is separated from the contact 23 and thus the signal source 3 is switched off from the input 5 will. The capacitor 29 keeps the relay 25 energized for a period of time which depends on its discharge time constant through the relay 25. Then the relay 25 is de-energized, the armature returns Action of the return spring 31 returns to the position shown, and the actual signal arrives back to the input 5, so that it energizes the relay coil 25 again after passing through the system 1.

The sizes of the relay coil 25 and the capacitor 29 determine the frequency of the modulation device 9 and thus the control signal. These Frequency is expediently chosen so that its period length coincides with the predetermined time period T. roughly matches.

The controller 11 of the device 13 operates in the following way: A storage capacitor 33 is normally from a DC voltage source 35 via line 37, a contact 39, a switch 41 normally in contact with it, another switch 45 normally in contact charged with a further contact 47 and a further line 51. Since the switches 41 and 45 controlled by the armature 27 of the relay 25, they move in synchronism with the chopper switch 21 and therefore with the control signal itself.

When the switches 41 and 45 in time with the control signal swing back and forth, they alternately cause the charging of the capacitor 33 and its discharge through contacts 49 and 55 into device 13, which may be a lamp or other display device can be. The device 13 is intended

ίο respond relatively slowly and are excited by the parallel capacitor 53 during the predetermined period of time T. If no control signal is received by the controller 11, then the device 13 will be de-energized after a time which is approximately equal to the predetermined time period T has elapsed. As long as the control signal has a shorter period than T , however, the capacitor 33 will periodically send electrical energy to the device 13 during the correct operation of the transmission system 1, namely at such a high speed that the device 13 during the correct operation of the system 1 is constantly excited. Any failure of an individual part in the system 1, its input 5 or its output 7, the signal source 3, the modulation device 9, the control 11 or the source 35 will therefore cause the device 13 to be de-energized after a time T after the occurrence of the failure .

Instead of a lamp or a similar display device 13, others can of course also be used Types of devices used for displaying. In Fig. 3, for example, a relay coil is used 57 as a slowly responding device 13. The armature 59 of the relay 57 actuates a switch 61 and connects the terminals 63 and 67 or the terminals 63 and 65 to one another, depending on whether the system 1 is working properly or not. The terminals 63, 65, 67 can be visible or audible warning or other display devices that indicate that the system is not working properly 1, or to devices that automatically switch off the signal generator 3, the voltage source 35 or Appendix 1 in a known manner.

It is by no means necessary that the modulation device 9 must be a passive chopper like him has been explained in connection with FIG. 2 and in which no special modulation voltage is used will. If it is desired to keep the roughly rectangular or square shape of the control signal, But to use this as an additional control signal, this can easily be done by a further power source 69, such as a battery, can be brought about, which is connected to input 5 via line 19 is connected, as shown in FIG. Every touch of the switch 21 with the contact 23 is then add the voltage from source 69 to the signal voltage at input 5. Preferably will an impedance 71 is connected between lines 17 and 19. The device 13 in Fig. 3 is also in of the plant of Fig. 4 to illustrate a complete set-up.

An example of a simple electron tube amplifier system 1 is shown in FIG. The amplifier has a vacuum tube 73, a triode which has an anode 75, a control electrode or grid 77 and a cathode 79. The latter can e.g. B. be indirectly heated and have a H filament. Of course, other types of amplifiers, for example tetrodes, pentodes, ma-

magnetic amplifiers, transistors, etc., whereby the number and type of amplifier stages can be arbitrary, be applied. The type of amplifier and the amplifier circuit are not essential for the invention, as long as there is only one signal input 5 and one output 7 in the system.

The anode 75 of the tube 73 is connected to the anode voltage source via the line 81 and the relay coil 25 83 connected, which is also connected to line 15. The signal source 3, which can be of any type can, for example, a voltage or current generator, a receiver, a transmitter, a signal indicator for Alternating or direct current, is via the line 15 to the cathode 79 and via the lines 17 and 19 is connected to the grid 77 via the chopper switch 21. The anode current of the tube 73 as a result of the signal on its grid energizes the relay 25, opens the switch 21 and switches the signal from the grid of the tube 73, as described in connection with FIG. ao

The same control 11 as in FIG. 2 can also be used in the system of FIG. 5. To also A somewhat different control 11 in the system of FIG. 5 is used to explain yet another possibility used. This control does not, as in the case of FIG. 2, provide full power to the final device 13 when the control signal appears at output 7, but at the end of the chopper period. Of the Armature27 of relay 25 is pulled down when relay 25 is not energized. When the Relay 25 moves the armature 27 upwards. This change can of course also be made in the appendix Fig. 2 and the other embodiments of the invention can be applied.

The voltage source 35 is connected to the switches 41 and 45 via the lines 37 and 51. the Voltage from source 35 is therefore rapidly switched between contact pairs 49-55 and 39-47. Through this voltage is applied via lines 85 and 87 to two further relay coils 89 connected in series and 91, with the latter having a capacitor 93 in parallel. The relay 91 works with very low voltage and does not need the full voltage of source 35 for its excitation. It remains therefore under current, although the voltage of the source 35 is only intermittently on the lines 85 and 87 is laid. As long as the controller 11 receives the control signal from the relay 25, the switch remains 95 separated from the contact 97, whereby an alarm circuit is kept open.

On the other hand, the relay 89 is chosen to have almost the full voltage of the source 35 for excitation needed. In this way, if the system is working properly, system 1 remains, since the periodic working switches 41 and 45 reduce the value of the voltage applied to lines 85 and 87, the relay 89 without power. If no control signal is picked up, however, the movements of the will be heard Switches 41 and 45 on, and switches 41 and 45 remain in an extreme position, so that the full voltage of the source 35 reaches the relay 89, whereupon the switch 99 touches the contact 101 and closes the alarm circuit. The relay 91 is also used to monitor the relay 89 because the relay coils 89 and 91 are connected in series.

Fig. 6 illustrates the invention as applied to a flame monitor. Here is the signal source 3 from a probe for monitoring a gas pilot flame. The same device can also be used with oil burners and other fuels.

The flame can be monitored either by means of a photoelectric cell or by means of a Flame probe take place as shown in FIG. 6.

The primary purpose of an electronic flame monitor for oil or other burners is it is to turn off the fuel when a certain unsafe condition occurs. Such a condition can failure to ignite the fuel or failure of combustion during operation of the burner. The flame probe uses the electrical conductivity of the flame to put into operation.

Parts of the electronic flame monitor can now fail, which must be recognized in good time must become.

By the embodiment of the invention according to FIG. 6, which is particularly suitable for the needs of a Flame monitor is set up, all caused by an error of the monitor are for the first time Dangers completely eliminated.

In Fig. 6 the flame monitor has a burner 103 with a gas inlet 105 and an ignition electrode 107 and an L-shaped flame probe 109, which is attached to the point where the flame is located target. The gas is generated by applying a high voltage from the transformer 111 between the Ignition electrode 107 and the burner 103 ignited. This voltage also serves as a source for the Flame monitor current that can flow through the flame to probe 109. If one is present Flame is between the line 17, which is connected to the probe 109, and the line 15, which is connected to the burner housing 103 is connected and grounded, a negative signal voltage is present.

The amplifier tube 73 is normally energized, and the negative signal voltage from that Flame detector blocks tube 73. The circuit is similar to that of Figures 2, 3 and 5, but has a few Deviations. As a direct current source 35, an alternating current transformer 113 is connected to a rectifier 115, a current limiting resistor 117 and a storage capacitor 119 intended. The capacitor 29 is parallel to the relay 25 and is connected to the resistors 121 and 123 connected, which produce the correct time constant for the relay 25 to drop out and the desired Cause the frequency of the modulation device 9 designed as a chopper. The relay 25 should have a large AC resistance. The armature 27 of the relay 25 also actuates a switch 41 the contacts 39 and 49. The relay 57 operates on a switch 61 which touches the individual contact 63 and the device 13, such as an alarm device or an indicator, from a further power source 125 powered. The device 13 can, however, also include the burner and the fuel supply system include, in which case, when the relay 57 is energized, a contact 65 is opened and on this Way an advertisement is brought about.

The device according to FIG. 6 operates as follows: In the absence of the flame monitor signal the tube 73 carries anode current, since the variable resistor 127 between the control grid 77 and the cathode 79 maintains the grid and cathode at approximately the same potential. The relay 25 is thus' energized and pulls the anchor 27 down. As a result, the chopper switch 21 touches the contact 23 Storage capacitor 33 is charged from the power source 35 via the switch 41, which is also of the Armature 27 of relay 25 moves against contact 39

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has been. However, the relay 57 is not energized and is contained in a common piston 141 with a

the device 13 ineffective. Diode rectifier 147, 149 is housed.

If a flame now arises, the probe delivers the cathode 139 of the photocell 133 is via a 109 a negative voltage via the lines 17 to line 151 and a resistor 153 with the anode 19 and 15 to the input 5 of the tube 73 between Git-5 147 the rectifier diode 147, 149 connected. The ter 77 and cathode 79 and blocks the tube 73. The cathode 149 of the diode is connected to one pole 157 of an alternating current network via a line 155 with time that elapses until complete blocking depends on the time constant of the resistor 127, the. The relative cathode-anode potentials of the parallel capacitor 129 and a series resistor photocell 133 are obtained by series resistors 131 in the line 19 to the grid 77 of the tube 73. io 155 ' and 157', which is connected between the line 151, which is connected to the relay 25, after the tube 73 has been blocked, to the cathode 139 of the photocell, and due to the charge of the capacitor 29, another line 161, which is connected to the other pole 159 of the white time kept under current. For this, the time network connects, lies. From the line 143 a constant discharge through the relay coil 25 and tap 163 is connected to the resistor 157 ' , the resistors 121 and 123 being decisive. If the 15 is de-energized, as a result of which a change in the potential of the anode 137 coil 25 , the switch 21 of the photocell opens. A capacitor 165 is under the action of spring 21. The capacitor in parallel with resistors 155 ' and 157'. 129 has in the meantime charged to the full negative signal voltage through the connection of the cathode 167 of the tube. After the dropping of the 141 via the line 169 with the line 161 and the relay 25 , the switch 41 closes the contact 49, so that the control grid 145 is connected to the anode 133 that the energy of the photocell stored in the capacitor 33 reaches the signal that in which photoin the control relay 57 arises via a further counter-cell 133 , to the input of the tetrode,
status 133 reached. The energized relay 57 causes the screen grid 171 to be connected to the already mentioned armature 59, the switch 61, to the contact line 155 . The anode current of the tetrode 63 to tilt, whereby the display device 13 flows from its anode 173 via the line 81, is excited by the source 125 and indicates that the relay coil 25 in the line 157. The armature 27 was satisfactory is working. the relay coil 25 closes either a variable

The negative voltage of the capacitor 129 flows ble series resistor 175 in the circuit of a slowly through the resistor 127 until the tube 73 photocell 133 illuminating lamp 177 briefly or again leads anode current and the relay 25 again 30 switches the resistor 175 on . The lamp 177 is energized, as a result of which the chopper switch 21 is closed via the line 179, which is recharged via the line oil to the line 159 of the network and the capacitor 33 is connected, either via etc. in constant repetition. The charge of the resistor 175 or, via the short circuit, the capacitor 53 keeps the relay 57 under current for a certain time through the closed switch 21 and contact 23, since there is a high resistance and 35 via the line 155 and the other side 157 of the has a low withstand voltage. The time it takes for the network to be formed is powered. In this fall of the relay 57 is the previously determined time-manner causing the periodic activity of the relay span T adapted, as in connection with FIG. 25 that the light intensity of the lamp 177 was discussed periodically in FIG. For the special case that fluctuates, i.e. is modulated. The modulation with FIG. 6 is about 2V2 seconds, a suitable delay is applied to the control signal in this way. The period of the modulation device signal source 3 is carried out. The upper part of the circuit 9 is therefore set to a value which is shorter processing with the controller 11 and the device 13 is than this time period and for the 1 second similar to the corresponding part of FIGS. 2 and 3 turned out to be useful Has. The mains rectifier 181 and the storage condenser

Any interruption or short circuit in the 45 sator 183 corresponds to the DC power source 35 of FIG

The input circuit of the tube 73 continuously holds the grid of FIG. 2.

and the cathode at zero potential and the relay 25. The device according to FIG. 7 is particularly energized. However, then no control signal advantage for fire and burglar alarm systems are formed, and the switch 41 is permanently against od. The like., Where disruption of the Lichtden contact 39, so that the relay remains energized 57th 5 ° beam of the lamp 177 or a failure of the light in a similar way interrupt all possible sources of error, the photocell, the amplifier or the other switching elements, such as electrode short circuits, causing an alarm.
and interruptions, the control signal and, in some embodiments discussed earlier, the relay 57 is de-energized. The grounding of the relay coil of the invention has not been caused by the feedback of the output 57 to keep it energized since the output signal to the input is disconnected by controlling the ungrounded end of its voltage source through the modulator 9 from the output using switch 41 is. When this end is made grounded. Of course, this is not necessary. relay 57 would of course be ineffective. In Fig. 8, for. B. the same system as in Fig. 7 The relay coil 57 could just as well be shown connected, except that the relay 25 is not that that it controls modulation ^{device 9 through the switch 60 at the two ends.} The modulation 41 and 45 is separated as shown in FIG. the light source 177 is here rather by an un-

The description of the invention has so far generated dependent modulation device 185 , the

Chopping or pulsating modulation of the actual control signal of suitable amplitude and frequency

borrowed signal that is generated between the signal on the main light beam. Should the modular

source 3 and Annex 1 was effected. In Fig. 7 65 tion device 185 fail, this is an example in which the modulation naturally takes place automatically through the disappearance of the tion on the signal source itself. In FIG. 7 the control signal and under certain circumstances also the signal source 3 is represented in the form of a photocell 133 by the disappearance of the actual signal, the anode 137 of which is noticeable via a line 143. Similarly, in each of the 7 ° FIGS. 2 to 6 connected to the control grid 145 of a tetrode, the switch 21 or another module could

tion device independently by any known Vibrating device, for example by an electric, piezoelectric or magnetic vibrator, be operated.

Another practical application of the system according to FIG. 8 is shown in FIG. Interrupt here Objects 187 on a conveyor belt, the light signal modulated by a control signal, which is transmitted by the Photocell 133 is recorded. Another relay 191, which has a capacitor 193 in parallel, is on Output 7 connected in series with relay 25. This relay 191 can operate a switch 195, which switches a counter 197 to determine the number of objects 187.

In the devices of FIGS. 7, 8 and 9, any other generator can be used instead of the lamp 177 provided if a suitable receiver is used instead of the photocell. If radio waves or sound waves are used, a corresponding radio or sound transmitter and a corresponding radio wave or sound wave receiver can also be used.

The explained embodiments of the invention can of course also be used in calculating machines or the like Circuits are used. However, Fig. 10 is a particular embodiment for special Calculating machines for a pulse counting and frequency divider circuit.

Pulses coming from a signal source 3 arrive via a line 201 and via a diode rectifier 203 to the control grid 71 of an amplifier tube 73. In the earth connection of the cathode 79 of the tube 73 is a resistor 205 for generating a bias voltage, and the tube 73 is normally locked. The bias at resistor 205 is only overcome when a predetermined Number of consecutive pulses is stored in the capacitor 207, which has a resistor 215 lies parallel. When the predetermined number of pulses from the signal source 3 is received the charge on capacitor 207 increases the voltage on grid 71 of the tube 73 so far that the tube 73 carries anode current.

The capacitor 207 is completely discharged via the ground lines 213 and 217 when the relay 25 is excited by the anode current and puts the switch 21 against the contact 23. That way leads the tube 73 once anode current for a certain number of input pulses, thereby making a count and frequency division takes place. The frequency division ratio can be changed by changing the Bias resistor 205 can be changed.

Here, too, the switch 21 modulates the input signal in front of the input 5 of the tube 73 with the control signal, namely by short-circuiting the capacitor 207 when the relay 25 is energized. The storage capacitor 33 is charged periodically via the resistor 43 between the terminals 5 + and B- of the power source and periodically sends energy to the relay 57, which actuates the control switch 61, as has been described above.

Instead of the modulation device controlled by a relay, other types of modulation can also be used are used, for which Fig. 11 shows an embodiment in which an output transformer in place of the relay 25 and known modulator circuits as a replacement for the switch 21 are. At the input 5 of the system 1, for example a tube 73, there is a modulated with a control signal Signal. The modulation device 9 can, for example, be a commercially available pulse generator or another control signal generator, the control signal through the system 1 only in the presence of the actual signal can be transmitted, as explained above.

The modulated signal is transmitted through the system 1 to output 7, where the control signal with a transformer 249 which is tuned to respond to the modulation of the

ίο signal responds. The upper terminal of the primary winding 251 of the transformer 249 is connected by the line 81 to the anode 75 of the tube 73. One connection is connected to an anode voltage source Z? +, whose negative connection terminal B- is connected to the cathode 79 of the tube 73 via the resistor 205. The control signal appears on the secondary winding 253 of the transformer 249. A capacitor 255 and a rectifier 257 are connected to the secondary winding 253. The rectified voltage of the control signal arises on a capacitor 259, which is parallel to a relay 261, which can open and close the contact 263 of a display device of any type, such as a warning system.

Because the transformer 249, which is the body of the output relay 25 assumes no direct voltage, but only alternating or pulsating voltages, like the control signal, the device of FIG. 11 completely monitors the circuit of the system 1. The capacitor 255 and the rectifier 257 monitor a possible short circuit in the Transformer 249, since in this case there is insufficient voltage across the capacitor 259 would to actuate relay 261.

Should feedback of a modulation device 9 instead of the independent modulation device 9 of FIG. 11, the contacts 263 can be in the same way as the switch 21 of Fig. 2 or 5 act on the input 5. Otherwise, the switch 21 can be as discussed above Embodiments of the invention themselves serve to strike a bell or some other display device to operate.

In order to avoid that several simultaneous errors of the system 1 the display of a correct operation cause the output circuit according to FIG. 12 instead of that of FIG. 11 for the system 1 be used. Here, a much larger voltage is used for relay 260, namely with the help of the 2: 1 transforming transformer 250, which is excited by the control signal. The time constant of the secondary winding 254 of the Transformer 250 and the relay 260 determine the predetermined time period T. The relay 260 is on AC relay, which preferably, but not necessarily, should drop out slowly, especially when the control signal has a fairly low frequency. Through the step-up transformer 250 failure caused by a short circuit between primary and secondary windings 252 and 254 is called does not result in a false display. Interruptions or short circuits anywhere in the system have the complete disappearance of the voltage in the relay coil 260 result. The relay 260 can be replaced by a DC delay relay, in which case a rectification similar to that of Fig. 11 can be used. The relay 260 and the display device can also be omitted Connect directly to the secondary winding 254 of the transformer 250.

Not only can a wide variety of output circuits and modulation devices be used be to apply the invention to any transmission systems, but it can also be the Line to the relay controlling the display device, which is outside the actual system, are monitored for correct operation. This is achieved by another relay that is used for Monitoring of the mentioned control relay is used. For the purpose of illustration, there is such a control relay monitoring system shown in FIG. 13 with a photocell circuit monitored in the manner of FIG is working.

The individual parts of FIG. 13, which correspond to similar parts of the system in FIG. 7, have the same reference numerals, so that the description of the circuit need not be repeated insofar as it corresponds to FIG. The photocell 133 is connected in such a way that at a minimum light intensity of the lamp 177 of the tetrode 141 it presses a control grid voltage which blocks the tetrode 141 and makes the relay 25 currentless. The diode 147 to 149 is installed in FIG. 13 in a separated from the Tetrodenkolben 141 piston 141 ', but could also be incorporated into the same piston 141, as shown in Fig. 7. The switch 41, which is controlled by the armature 27 of the relay 25 and the pair of contacts 39-49, could also perform the function of the switch 45 and the pair of contacts 47-55 of FIG would charge the rectifier 181 in one position and discharge into the relay 57 in the other position. This energy supply is brought about in FIG. 13, however, by a further relay 257 , to which a capacitor 253 is connected in parallel and which lies in a circuit which runs from the left connection terminal of the capacitor 33, via the line 48, to and through the relay coil 57 , via the line 46 to and through the further relay 257, via the line 44 to the contact 49 and through the switch 41 and the resistor 43 to the right side of the capacitor 33. The relay 257 serves as a monitoring relay for testing the control relay 2, which is preferably heavy-duty. The monitoring relay 257 preferably drops out with a delay, for reasons to be explained later.

The modulation with the control signal takes place in a similar manner as in FIG. 7 with the aid of the switch 21. The lamp 177 lights up when the switch 21 touches the contact 23 and closes a circuit that goes from the contact 23 via the line 80 to a Side of the lamp 177 goes and via the line 82, the resistor 175 to a contact 6, through a switch 4 actuated by the armature 10 of the control relay 2 to a side Ll of an alternating current source Ll-L 2 fused at Fl, further through the power source of the L 2 side, back via the line 12 and a switch 261 actuated by the monitoring relay coil 257 to a contact 22 and then via the lines 16 and 18 to the other side of the lamp 177 . When the switch 21 is opened, the lamp 177 therefore goes dark, makes the tube 141 live and sends current to the relay 25, which closes the switch 21 again, and so on, as explained above.

It must now be explained how the control relay 2, which is located outside the transmission system 1, is monitored by the monitoring relay 257. While the actual signal is being chopped up by the switch 21 , the capacitor 33 is charged periodically and periodically sends its charge to the two capacitors 53 and 253, which are parallel to the relay 57 and the monitoring relay 257, respectively. The two relays 57 and 257, which are slowly de-energized, are thus kept continuously energized during the correct operation of the system.

The switch 61 of the relay 57 touches the contact

ίο 60 and is connected via line 20 to control relay 2, which is also connected to network L1. However, the relay 2 will not operate until the resistor 175 is connected to the other side L 2 of the network. When the monitoring relay 257 is working, it establishes this connection with L 2 via a further fuse F2, a contact 14 and via the switch 261 of the relay 257 and the line 12 . The resistor 175 prevents the working monitoring relay 257 from causing a short circuit between the lines L1 and L2. However, this resistor 175 also serves as a load resistor for the fuse F 2. In this way, the control relay 2 operates and causes the switch 4 'controlled by its armature 10 to excite the display device 13 from the source L1-L2, all in one Circuit from the left side of the device 13 through the switch 4 'to the contact 24, via the line 28 to the contact 26 and via the switch 4 to the line Ll, through the power source to L 2 and directly to the right side the device 13 runs. During the attraction, the relay 2 interrupted the described connection between the line L 1 and the resistor 175 and instead connected the line L1 to the line 28.

In the event of errors in the system, control relay 2 drops out before monitoring relay 257 , which is slowly de-energized, drops out. This sequence avoids a temporary short circuit between the lines Ll and L 2, which would otherwise occur via the line 28 and cause the fuse F1 to respond unnecessarily. In this way, the control relay 2 is constantly monitored for correct operation, since the fuse Fi breaks down if either the monitoring relay 257 or the control relay 2 does not drop out, for example if it should get stuck. On the other hand, the circuit described above with the resistor 175 causes the fuse / ^ to break down if either the monitoring relay 257 should not drop out or the control relay 2 should not pick up.

The following overview shows that the monitoring device according to FIG. 13 works without any gaps in which the reactions to the occurrence of the various errors are given.

failure

reaction

Relay 57 does not work.
Relay 257 does not work.

Relay 57 does not work,
but relay 257 works.

Relay 25 does not flip.

Modulation at input 5
does not appear at output 7.

Relay 2 does not work.
Relay 2 does not work.

Relay 257 blows fuse F 2 .

Relays 57, 257 and 2
fall off.

Relay 25 does not flip.

failure

Monitoring circuit open.

Relay 57 does not drop out.

Relay 257 does not drop out.

Relay 2 does not drop out.

reaction

Lvcine light modulation. Relay 25 does not flip.

Fuse F 1 breaks down because relay 257 drops out and shorts the circuit across Ll and L 2 before relay 2 drops out.

Relay 2 short-circuits the circuit via Ll and L 2 when it drops out and blows through fuse F 2.

When it drops out, relay 257 shorts the circuit across Ll and L 2 and blows through fuse F 1.

Should it be desired to omit the monitoring of the control relay 57 from FIG. 13, this can be done can be achieved by shorting lines 44 and 46 and lines 18 and 82 to the power lines Ll and L2 connects. The switch 261 and the contact 6 now control the display device 13th

While the described monitoring of the control relay 57 of particular expediency in the after of the systems monitored by the invention, it is also valuable in itself. You can z. B. with advantage can be used wherever the correct operation of a contact relay is to be checked. A somewhat modified relay monitoring is shown in FIG. 16, where the individual parts have the same reference numbers as the corresponding parts in FIG wear.

When a low-voltage switch S1 is closed for the purpose of supplying power to the device 13, a circuit is closed which is controlled by the power line L2, through the fuse / ⁷ !, Via the line 12, the contact 22, the switch 261, which is controlled by the monitoring relay 257 , a resistor R2 and a resistor R3, to and through the monitor relay coil 257. The circuit continues via a rectifier 181, a small resistor R4, a line 102, via the closed switch 5 * 1 and then via a line 100 through a resistor R1 to a contact 6. From the contact 6, the leads in this way closed circuit through the switch 4 controlled by the armature 10 of the control relay 2 to the other side L 1 of the power line.

The monitoring relay 257 is energized in this way and attracts its armature 105, whereby a further switch 106 carried by the armature is placed against a contact 108. This closes a circuit that excites the control relay 2 and runs as follows: From the upper connection of the control relay 2 via the line 110 to the contact 108, via the switch 106, the line 102, the control switch S1 and the line 100 to the fuse F2, on another switch 112, which is actuated by the armature 105 of the monitoring relay 257, to a contact 114 which is connected via the line 12 to the power line L2. Since the lower terminal of the control relay 2 is connected to the power line Ll, the control relay 2 is energized.

The energized control relay 2 connects the left side of the device 13 via the switch 4 ', which is moved by the armature 10 of the energized control relay 2, via the contact 24, the line 28, the contact 26 and the switch 4 with Ll. Since the right side of the device 13 is continuously connected to L2, the device 13 is energized in this way. The monitoring relay 257 does not drop out when the switch 261 is lifted from the contact 22 because the charge stored in the capacitor 253 will keep the monitoring relay 257 energized until the control relay 2 operates and brings the switch 4 'into contact with the contact 24 . When the control relay 2 is energized, the travel of the monitoring relay 257 is changed in the manner explained and the polarity of Ll and L 2 with respect to the monitoring relay 257 is reversed. Of the

So holding circuit for the monitoring relay 257 then goes from the line L1 via the switch 4, the contact 26, the resistor R 3, the monitoring relay 257, the rectifier 181, the resistor R 4, the line 102, the control switch S1, the line 100 , fuse F2, switch 112, contact 114 and line 12 to power line L 2.

If the control relay 2 does not drop out due to mechanical faults after the control switch 5 "1 is open, the circuit that contains i? 2 is switched from Ll via switch 4 and contact 26 of control relay 2, via R2 and via switch 261 and contact 22 of the monitoring relay 257 closed after L2. As a result, the current rises through 7-2 until the blown fuse-F1 interrupts the circuit to device 13. Resistor R2 prevents the increasing current from damaging the relay contacts 257, before the control relay 2 can work, and its working path runs through the circle with R2.If this circuit is broken, such as with dirty contacts or because of the interruption of the resistor R2, because of a broken line or because of other reasons, then the device can 13. In this way, the correct continuity of the current is automatically monitored every time the control unit is started will.

If the contacts 261 and 22 stick when the switch S1 is closed, the fuse F1 breaks down when the switch 4 touches the contact 26 of the control relay 2. Should the contacts 261 and 22 stick in such a way that they prevent the switch 106 from touching the contact 108, then the control relay 2 cannot operate. If the hanging contacts 261 and 22 prevent the switch 106 from touching the contact 108, but 112 and 114 close, then the fuse F 2 will blow. This results from the circle that goes from L2 via 112 and 114, via fuse F2, via R1, via contacts 6 and 4 to L1.

If the contact 26 and the switch 4 of the control relay 2 stick when the switch ^ 91 is open, the monitoring relay 257 is triggered, which in turn closes the circuit via 261 and 22, so that Fl breaks through.

When the contact 24 and the switch 4 'des

Control relay 2 jam or stick, but 4 and 6 close, the monitoring relay 257 does not drop out when the switch S1 is opened and the fuse F 2 blows. The holding circle for the

909 510/304

19 20

wachungsrelais 257 runs from LI, via the front of the relay 25 and a capacitor 29 in parallel.

direction 13, the adhesive contacts 24 and 4 ', R3, the monitoring according to the invention takes place in one

via the monitoring relay 257, the rectifier manner as it was already in connection with the earlier

181, resistor R 4, contacts 106 and 108 and * embodiments of the invention described

via the control relay 2 to Ll. But when the con-5 was. The chopper switch 21 periodically sets the

glue bars 24 and 4 'and also the contacts 4 and control grid 408 of the tube 404 to earth and

Keeping 26 closed, then closing the contacts 26 interrupts the transmission of the signals from the microphone

and 4 the two relays briefly. This can be traced 400 to the entrance of the tube 404.

from Ll via the control relay 2, via the contacts If a thermostat 426 has a temperature

106 and 108, via the monitoring relay 257, requests an increase in IO, a primary burner control

contacts 26 and 4 and back to Ll. The tion 428 actuates the burner motor temporarily

Monitoring relay 257 drops out, the circuit is activated 402. If the noises that are the proper

closed, and the fuse Fl breaks through, so accompany moderate combustion, not within a few

that the device 13 is de-energized. recorded by the microphone 400 in seconds

The monitoring relay 257 should have a large 15, approximately within 10 seconds of the resistance, to prevent the control relay 2 from starting the burner motor 402, switches the primary, via the coil of the monitoring relay 257 burner control 428, automatically preventing the burner motor from still working, when contacts 106 and 108 close-402 off. If the right noises from the microscope sticking together. Although this state is recorded in the monophone 400, the control relay direction according to FIG. 13 cannot occur because the 20 57 energizes and pulls the switch 61 against the Kon monitoring relay 257 there from a separate clock 63, which causes the burner motor 402 is aroused in activity source, it is preferable to keep one here as well. Should there be any fault in the on-monitoring relay with high resistance to displacement 1, in the signal source 3, in the modulation, which slowly falls off. An alternating current relay operating with direction 9 or in the controller 13 could also be used, in which case the switch 61 and the burner motor 402 circuit according to FIG. 16 can be used, which is switched off. Secondary controls 430, as rectifier 181 can be dispensed with. Safety switches and the like can be used in a known manner

Fig. 17 illustrates another example of being provided.

the uses of the invention. Here Figs. 14 and 15 illustrate typical ones it is an acoustic flame guard 30 mechanical embodiments of the invention. In The one that is involved in the combustion of oil or other Fig. 14 shows a train braking system which Noises produced by fuels are monitored. should be monitored continuously and automatically. this For this purpose a signal source 3 is in the form of an example of how the invention is based on a pressure Microphones 400 placed in the vicinity of the control burner chamber, which does not work with liquids or gases, are well shielded. 35 systems can be used. In the braking system The microphone picks up the noise that can be made by the main valve 300, which has a three-way inlet Accompany combustion inside the chamber, when activated, in the driver's cab of the locomotive Burner motor 402 is in operation. The engine 402 builds while a pressure line 1 on the controls in a known manner the flow of fuel over the entire length of the train with different, along the to the burner. 40 line-mounted shut-off valves 301, 302, etc.

The microphone 400 is extended with the input 5 one. A first vacuum tube 404 is connected to input 5, which has an anode source 3, the pressure medium as a flowing signal 406, a control grid 408 and a cathode 410. sends. A vent line 304 with a direct control valve 303 maintains a minimum pressure in contact with the control grid 408, the lower port 45 is connected to ground when the main valve 300 is open when the main valve 300 is open, here labeled B-. This is and the release of the cathode 410 of the tube 404 by the pressure medium has a suitable pre-established device, for example the voltage shown schematically and is desired via a decoupling member 412 with braking devices 305 provided. connected to the earth terminal B— . A modulation device 9 in the form of a mechanical resistor 414 is parallel to the microphone 400. 5 ° nical pulse generator sends periodic con-

The anode current of tube 404 comes from the trollsignale, which modulates the signal in input 5

Anode 406 to a filter network 416, which is also Heren. The control signal pulses sent by the module

may contain further amplifier tubes. The filtering device 9 must be created

network 416 and the decoupling element 412 have a lower pressure than that for actuation

tuned accordingly, so that certain tone stimulation of the brakes 305 required pressure,

sequences that are characteristic of the combustion In output 7 at the other end of the train

noises are in a particular burner, from which a membrane 306 is provided in a housing 307,

remaining sound frequencies are filtered out. One into which the line 1 opens. The membrane 306 is like this

Knowing the minimum tone intensity makes the amplifier 404 set that it is as a result of the control signal pulses

live, so that quieter, sporadic noises ^{vibrate 6} °, whereby a wave by means of a spring 308

in the same frequency band the tube 404 is not vibrated 309 and the control signal

can influence. is recovered. A rotatable anchor 310 is

The filter network 416 is followed by an end tube 418, pivoted as the shaft 309 swings back and forth. which operates as a cathode amplifier and its anode Thereby, touch the contacts 311 and 312 off 420 to the B + terminal of the anode current source ⁶ 5 partly contacts 313 and 314. When connected to the anode voltage for the contacts 312 and 314 touching each other, the anode 406 of the tube 404 will deliver. The output of the capacitor C through a current limiting resistor filter network 416 is between the control grid was R from an energy source 315 charged. Be-422 and the cathode 424 of the end tube 418. In contrast, the contacts 311 and 313 stir, so the cathode output circuit 4 of the end tube 418 is 7o the energy stored in the capacitor C.

sent into the relay 57, which is only de-energized again with a delay. The parallel capacitor 53 keeps the relay 57 energized as long as the control signal appears at output 7. As with the electronic Embodiments of the invention, the period duration of the control signal must be smaller here as well than the specified delay in de-energizing relay 57.

Any fault along the pressure line 1 or in the storage (pressure medium) source 3 or in the modulation device 9 or in the output device 7 etc. causes the relay 57 to be de-energized, whereby the contacts for an alarm device or a display device are closed. In this particular example, the brakes 305 are parallel to the pressure line 1, but series connections can also be used. When the brakes 305 are actuated, the alarm device is automatically triggered. If this is not desired, a switch for breaking the alarm circuit can be connected to the main valve 300, which prevents the alarm device from being triggered when the brakes are applied. If, on the other hand, the alarm device is allowed to work when the brakes are applied, the alarm circuit is automatically monitored, thereby monitoring the entire system.

A simple alarm circuit is shown in FIG. It contains a lamp 316 that periodically lights up when the system is working properly, but lights up continuously or remains dark when there is an error occurs of any kind in the monitored system or in the alarm system itself. If there is a modulation should be desired by feedback, this can be done by actuating the pulse generator 9 with With the help of two contacts (not shown) that are periodically moved by the armature 310. Only by reversing the pressure conditions, the system of FIG. 14 can be operated as a vacuum system will.

While in the system of FIGS. 14 and 15, the brakes or other devices 305 by application are moved by pressure, other known systems can also be equipped with the invention become, such as B. Systems with pressure compensation, in which a pressure drop causes the system to become unbalanced brings and activates the brakes or other devices.

Claims (15)

Claims ·. 1. Procedure for monitoring a mechanical or electrical transmission system Signals by means of a control signal given to the input of the system with a not in the actual signal present frequency or frequencies, characterized in that the The actual signal can be modulated with the control signal and that through the output of the system frequency-sensitive means again separated from the actual signal a control signal Device can be fed, which triggers a display or a process when the control signal for a time that is greater than the period of the control signal. 2. The method according to claim 1, characterized in that at the output of the to be monitored A device is provided that responds to the mechanical or electrical signals, which in turn generates a control signal as long as it arrives at the output of the system, and that the transmitted mechanical or electrical signals can be modulated with this control signal are. 3. Device for performing the method according to claim 1 or 2, characterized in that that a modulation device for modulation at the input of the system to be monitored the actual signal with the control signal and a device is provided at the output is that triggers an indication or an action when the control signal is for a time fails, which is greater than the period of the control signal. 4. Device according to claim 3, characterized in that the of the to be monitored System-independent modulation device the actual signal at its source with the control signal modulated. 5. Device according to claim 3, characterized in that the the actual signal on Input modulating modulation device in time with the control signal periodically between two-state toggling relay is that with the output of the plant like this connected is that it is triggered when the actual signal arrives at the output of the system and then carries out its periodic tilting movement as long as a signal at the output of the Plant arrives. 6. Device according to claim 5, characterized in that the relay has a switch in The input circuit of the system opens and closes periodically in the cycle of its tilting movement. 7. Device according to claim 3, characterized in that between the output of the to monitoring system and the device triggering the display or the process a control is provided for this device, which operates with a delay approximately equal to that Is the period of the control signal. 8. Device according to one of claims 3 to 7, characterized in that the output the system, a display or a process triggering device from the on Output of the system incoming control signal in its clock periodically from an energy source is excited and has a response time which is at least equal to the period of the control signal is such that the device triggers the display or action when the excitation for a There is no time that is greater than the period of the control signal. 9. Device according to claim 8, characterized in that the display or the process Triggering device by a relay that tilts back and forth in time with the control signal is periodically connected to an energy source. 10. Device according to claim 8 or 9, characterized in that the the device periodically exciting circle, e.g. B. the relay is tuned to the frequency of the control signal. 11. Device according to claim 8 to 10, characterized in that the device periodically Exciting relay from the device used as a modulation and generating the control signal Relay is controlled. 12. Device according to claim 11, characterized in that that the device periodically Exciting relay and the relay generating the control signal are combined into a single relay are. 13. Device according to claim 9, characterized in that the energy source is a capacitor is that of the back and forth toggling relay in the cycle of the control signal alternately with a voltage source and connected to the device triggering the display or the process is. ίο 14. Apparatus according to claim 8 and 9, characterized in that between the display or the operation initiating device and the forth in time with the control signal and herkippenden relay another relay arrangement is seen upstream, the triggering of a display or a process also causes if only the to-and-fro relay is not working properly works and z. B. strives to energize the device continuously. 15. Device according to one of claims 3 to 14, characterized by its application on the monitoring of systems for the transmission of light and other radiation sources, z. B. by photocells or by from the radiation source influenced electrical resistances, generated electrical signals, for example of flame monitors. Considered publications:
German Patent Nos. 686 079, 699 952;
Swiss patent specification No. 230 384. In addition 4 sheets of drawings © 909 510/304 5.