DE1143867B - Bistable circuit with a Ferreed relay with changeover contact - Google Patents

Description

Bistable circuit with a Ferreed relay with changeover contact In electronic switchgear, control and regulation systems (e.g. communications technology, telephone exchange technology) there is often the demand to use digital memories (flip-flop stages). Such circuits have so far been made available in various designs from Z. B. tubes, transistors, switching cores, etc. are known. It is also known use polarized relays for flip-flop circuits. These have the advantage that to maintain one of the two switching states no electrical energy is required and that, without changing the switching state, this for any Control and audit purposes is available. On the other hand, they have the slower disadvantages Switching time and the relatively high. Costs.

Clear switching ratios and significantly shorter switching times on the other hand a control arrangement for protective tube contacts, in which the control is carried out Shifting the actuating magnetic flux from one through two to either side of the contact armature pair arranged permanent magnets formed flux path to an over the contact armature pair extending flow path or vice versa takes place. This in the Anglo-Saxon Literature also referred to as Ferreed contact arrangement comes with a low Excitation from.

In the case of Ferreed contact, z. B. one sawn through in the middle Ferrite toroidal core, as it is known from storage technology, or two elongated ones Cores, half on both sides of a protective tube contact. Each toroidal core half carries a winding. Is only one of the windings energized or are both windings excited in the same direction, both ferrite core halves are in the same direction magnetized. The magnetic flux closes over the two halves of the toroid. A Flow over the working air gap between the two toroidal core halves of the contact arm: rpairs does not come about. If, however, a corresponding control current in a or both windings achieved that the toroidal core halves on their opposite Ends have the same polarity, so the flux shifts to the contact armature pair and closes via the working air gap with the effect that the protective tube contact is closed (ETZ, A, 1960, H. 25, p. 884, Fig. 9).

Recent studies show that it is sufficient to determine the state of magnetization to change one of the permanent magnets by a certain amount in order to shift the flux to effect the contact anchor pair. A reversal of magnetization is therefore not in everyone Case required. The object of the invention is to eliminate the disadvantages of a polarized Avoid relays by using such a Ferrreed relay.

The invention relates to a non-stable circuit with a Ferreed relay with changeover contact and is characterized in that in each of the two possible Magnetization states of the Ferreed relay the state of charge of one in series with whose field winding lying capacitor, which has a limiting resistor is at the respective input potential, after closing one of the layers of the capacitor the new magnetization state via the field winding short-circuiting switch of the Ferreed relay.

According to an expedient embodiment of the invention, it becomes the discharge circuit closing switch formed by the contact armature of a protective gas relay, whose A control pulse flows through the winding.

In another advantageous embodiment, it becomes the discharge circuit closing switches through the emitter-collector path of a switching transistor, whose emitter-base path is traversed by a control pulse.

According to a further embodiment of the invention, the Ferreed relay is with Changeover contact through the interconnection of two Ferreed relals with simple Contacts replaced, of which one contact each with the same magnetization state closed and the other open and their associated windings in series are switched. In such an embodiment is to avoid a short circuit of the supply voltage with a possible overlap of the switching processes a center-tapped current limiting choke between the two contacts and the common connection laid.

According to a further embodiment of the invention, several bistable circuits to a binary counter .be done one after the other.

In the following, the schematic representations according to the invention will be illustrated with reference to FIG Circuit arrangement explained in more detail.

Figure 1 shows an embodiment of the circuit arrangement according to the invention; Figure 2 shows its voltage curve; Figure 3 shows another version of the Ferreed Relay and Fig. 4 a circuit improvement of the circuit according to Fig 3.

In Figure 1, the rectangle marked 1 represents a Ferreed changeover relay is. Is the changeover contact 6 in the upper position shown and is the Input 18 z. B. connected to the 0-volt terminal, the capacitor 3 is over charged the resistor 16 to a voltage of 2U volts, so that the right The surface opposite the left surface has a positive potential. Is now for example the electromagnetic protective contact relay drawn as a rectangle 2 through a If a pulse of the appropriate length is excited, contact 4 closes and the capacitor 3 can discharge via the field winding 5 and the Ferreed relay 1. By the discharge current flowing through the excitation winding 5 becomes the Ferreed relay 1 'switched to the lower position. Since relay 2 has dropped out in the meantime contact 4 opens beforehand. The contact 4 can here by a Switching transistor to be replaced.

If a voltage 2 U is then subsequently fed to input 18, so the capacitor 3 is charged again to a voltage of 2 U volts. However is now the polarity of the documents opposite to the case described above, there the changeover contact 6 was in the lower position at the beginning of this process. If the winding 7 of the relay 2 is then energized with a control pulse 8, so contact 4 closes again and the capacitor discharges again via the Coil 5 of Ferreed Relay 1. Because of the opposite charge on the capacitor 3 the current flows through the coil 5 in the opposite direction: This has the consequence that the original magnetic state is restored. This change to the Magnetic state has the consequence that the contact turns back into the upper layer. This shows; that depending on which potential the input receives, the Ferreed relay 1 can be switched from one to the other bistable state.

If, for example, the state shown in Figure 1 is still used as the basis, input 18 was at -f-2 U volts from the last switchover, and the contact switched to the upper switch position shown after a control pulse 8 was applied. It is now assumed that the input 18 also remains connected to the voltage 2 U.

As a consequence; that the capacitor 3 discharges through the resistor 16; since both are indirectly at the same voltage 2 U. A control pulse 8, which causes the relay 2 to respond and thus causes the contact 4 to close, does not change the state of the Ferreed relay 1, since the capacitor 3 is discharged. The same applies if the arrangement (input 18 to 0 volts) has switched the changeover contact 6 to the lower position with a first control pulse 8 and a further control pulse 8 energizes the relay 2 with an unchanged input. This circuit has the same working conditions as one of the known bistable memory stages, ie it is switched depending on the information at input 18 (2 U or 0) when the clock pulse 8 arrives, or it remains in its previous position.

If, on the other hand, a fixed voltage of U volts is applied to input 18, so if you do not give any changing information to the input, the capacitor becomes 3 charged to a voltage U with alternately reversed potential. The circuit then works as a binary coaster or divider stage. For the control pulse series 8 (Fig. 2) the voltage curve 10 is obtained.

It does not matter whether the function sequence described first or second based on, can by interposing appropriate logical links, (e.g. and-or-gates) complete logical programs of any kind being constructed.

For the circuit to work properly, only consider that the charging current of the capacitor 3 is small compared to the discharging current, since both Currents flow through the coil 5 of the_Ferreed-Relais 1, and must be prevented that the charging current is a permanent change in the magnetic state and thus the switching state of the Ferreed relay 1 causes.

If, for special reasons, no Ferreed relay with changeover contacts 1 is to be used in the picture, this can be replaced by two Ferreed relays 1 u, each with one normally open contact, as shown in Figure 3. These two relays are switched so that when one contact is closed, the other is open. With this circuit you can. possibly close both for a short time. In order to avoid a short circuit of the supply voltage, it is necessary to switch on a current limiting choke at points 11, 12 and 13 (Fig. 3 and 4).

The above-mentioned bistable circuits can be easily cascading into a binary counter.

Claims (1)

PATENT CLAIMS: 1. Bistable circuit with a Ferreed relay with changeover contact, characterized in that in each of the two possible magnetization states of the Ferreed relay (1) the state of charge of a capacitor (3) lying in series with its exciter winding (5), the is connected to the respective input potential (18) via a limiting resistor (16), after the closing of a switch (4) short-circuiting the layers of the capacitor (3) via the field winding (5), the new magnetization state of the Ferreed relay is determined (Fig. 1). z. Bistable circuit according to Claim 1, characterized in that the switch closing the discharge circuit is formed by the contact armature of a protective gas relay (2), the winding (7) of which is traversed by a control pulse (Fig. 1). 3. Bistable circuit according to claim 1, characterized in that the switch closing the discharge circuit is formed by the emitter-collector path of a switching transistor, the emitter-base path of which is traversed by a control pulse. 4. Bistable circuit according to claim 1 or the following, characterized in that the Ferreed relay with changeover contact is replaced by the interconnection of two Ferreed relays with simple contacts, of which one contact is closed and the other is open and its associated with the same magnetization state Windings (5a, 5b) are connected in series (Figure 3). 5. Bistable circuit according to claim 4, characterized in that a center-tapped current limiting throttle is placed between the two contacts and their common connection to avoid a short circuit of the supply voltage in the event of a possible overlap of the switching processes (Figure 4). 6. bistable circuit according to claim 1, characterized in that several bistable circuits are connected in series to form a binary counter.