DE1299024B - Circuit arrangement for a gate circuit for short switching times for the use of indigital short-time meters - Google Patents

Description

The invention relates to a circuit arrangement for a gate circuit for short switching times for use in digital timers.

There are gates for digital timer known that from a main gate arranged between a counting pulse generator and a counter with associated main gate control multivibrator and also from a start impulse gate, a start impulse gate control multivibrator and a stop impulse gate and a retarder and a reset pulse generator.

The structure and the mode of operation of such a gate circuit are illustrated in FIG. 1 of the drawing explained in more detail: The main gate control multivibrator 5 is assigned to the main gate 2 arranged between the counting pulse generator 1 and the counter 3. The opening input 6 of the main gate control multivibrator 5 is preceded by a start pulse gate 9 with an input for start pulses 8, the closing input 7 of the main gate control multivibrator 5 is a stop pulse gate 14 with an input for stop pulses 13. The control input 15 of the stop pulse gate 14 is connected to the output 4 of the Main gate control multivibrator 5 connected. The start pulse gate 9 is assigned a start pulse gate control multivibrator 10 , the opening input 11 of which is connected to the output for readiness pulses 17 of the reset pulse generator 19 and whose closing input 12 is connected to the output for gate closing pulses 16 of the main gate control multivibrator 5. The delay 20 arranged in front of the reset pulse generator 19 is also connected to the output for gate closing pulses 16. The reset pulse output 18 of the reset pulse generator 19 is connected to the counter 3. A start pulse entering the input for start pulses 8 switches the main gate control multivibrator 5 to the open position, the main gate 2 is opened and the pulses from the counting pulse generator 1 reach the counter 3.Simultaneously with the main gate 2, the stop pulse gate 14 is opened. A stop pulse following the start pulse thus passes from the stop pulse input 13 through the stop pulse gate 14 to the closing input 7 of the main gate control multivibrator 5 and switches it to the closed position. At the same time, the stop pulse gate 14 is also closed again. The gate closing pulse appearing at the output for gate closing pulses 16 switches the start pulse gate control multivibrator 10 into the closed position and thus closes the start pulse gate 9. At the output for reset pulses 18 the reset pulse for resetting the counter 3 appears. At the output for ready pulses 17 a ready pulse appears which is delayed compared to the reset pulse. It reaches the opening input 11 of the start pulse gate control multivibrator 10 and causes the start pulse gate 9 to open. The circuit is thus prepared for the next measuring cycle.

Another gate circuit is known, that of the one described differs in that the start pulse gate control multivibrator 10 is not just the start pulse gate 9, but also the stop pulse gate 14 is assigned at the same time. The basic one However, the mode of action is the same. Both gates have the following disadvantages afflicted: If a start pulse hits the start pulse input during the previous readiness pulse initiated opening switching reaction of the start pulse gate at the start pulse input and the start pulse is followed by a stop pulse in such a way short time interval that he is also still in the opening switching reaction of the Start impulse gate falls, it can happen that this stop impulse does the main gate is closed, but no longer the start impulse gate itself Stop impulse following start impulse thus passes through the start impulse gate and triggers the opening of the main gate again. Enter this reopening of the main gate before the counter receives the reset pulse triggered by the previous stop pulse received, there is a significant measurement error.

It has already been suggested to use a gate's response time to shorten a gate control multivibrator by adding another gate control multivibrator to the gate is assigned. In this case, the reaction time is shortened one that one gate control multivibrator controls the opening and the other controls the closure of the Tores takes over. In this way, the response time of the start pulse gate shorten it so that it coincides with the response time of the main gate. But even with the use of this measure, the further disadvantage remains, that a stop impulse following and still in the closing reaction of the main gate falling start impulse passes the start impulse gate and the main gate again during of the measuring cycle initiated by the previous start pulse, i.e. before Resetting the counter, opens. It is the purpose of the invention to eliminate these possible errors to avoid and thereby the reliability and the range of application of gate circuits to enlarge.

The invention is based on the object of preventing switching pulses, the short time after the stop impulses or during the closing reaction of the main gate arrive at the start pulse input, which was initiated by the previous stop pulse Prevent the closing reaction or the main gate again before the end of a measuring cycle to open.

According to the invention this object is achieved in that the closing input of the Startimpulstor control multivibrator with an output for switching pulses that are derived from the opening switching reactions of the main gate control multivibrator, connected is. This closes the start impulse gate when the Main gate opens. When a stop impulse arrives, the start impulse gate is already open closed, and even in a short time interval following start impulses can do not pass the start impulse gate before the counter is reset. It is furthermore expedient, the opening input of the Startimpulstor control multivibrator with an output, the readiness pulses or other opposite the reset pulses emits delayed pulses to connect. When using two start pulse gate control multivibrators and a start impulse gate with two control inputs is a connection of the closing input of a start impulse gate control multivibrator with the output for main gate opening impulses and a connection of the opening input of the same start pulse gate control multivibrator with an output for reset pulses is useful. The opening input of the other start impulse gate control multivibrator is connected to the output for readiness pulses and the closing input with the output for main gate closing pulses of the main gate control multivibrator.

The invention is to be described in more detail below on the basis of two exemplary embodiments explained. In the accompanying drawing, FIG. 2 a gate circuit with a start pulse gate control multivibrator, FIG. 3 a gate circuit with two Start impulse gate control multivibrators.

In the gate circuit according to FIG. 2, a main gate 2 is arranged between a counting pulse generator 1 and a counter 3. The opening input 6 of the main gate control multivibrator 5 is connected via a start pulse gate 9 with an input for start pulses 8 and the closing input 7 via a stop pulse gate 14 with an input for stop pulses 13. The start pulse gate 9 is assigned a start pulse gate control multivibrator 10, whose closing input 12 is associated with an output for main gate opening pulses 21 of the main gate control multivibrator 5 is connected. The opening input 11 of the start pulse gate control multivibrator 10 is connected to the output for readiness pulses 17 of a reset pulse generator 19. A delay 20 is arranged between the reset pulse generator 19 and the output for main gate closing pulses 16 of the main gate control multivibrator 5. In addition to the output for readiness pulses 17, the reset pulse generator 19 also has an output for reset pulses 18 for resetting the counter 3 . The control input 15 of the stop pulse gate 14 is connected to the output 4 of the main gate control multivibrator 5.

The function of the circuit arrangement according to the invention can be understood from the description of the following sequence: When a measurement is terminated by a stop pulse at the input for stop pulses 13, the delay 20 is triggered by the gate closing pulse emitted by the main gate control multivibrator 5 via the output for gate closing pulses 16 initiated. After the delay time has elapsed, the delay 20 emits a pulse which triggers the reset pulse generator 19. The reset pulse generator 19 emits a reset pulse to the counter 3 via its output for reset pulses 18 and returns it to its initial position.

Moreover, the reset pulse generator 19 outputs, via its output for standby pulses 17 a relative to the reset pulse delayed ready pulse to the opening of the entrance 11 of the Startimpulstor control multivibrator 10 and causes the opening of the start pulse gate 9. true now a start pulse at the input for starting pulses 8 a, so it reaches the Opening input 6 of the main gate control multivibrator 5 and causes the opening of the main gate 2. While the main gate control multivibrator 5 tilts into the open position, it emits an impulse to the closing input 12 of the start impulse control multivibrator 10 via its output for main gate opening impulses 21 and causes the closure of the start impulse gate 9. At the time of a subsequent stop impulse, the start impulse gate 2 is already closed, or its closing reaction has already been initiated. Since the start impulse gate 9 is only opened again by the ready impulse triggered by the stop impulse and delayed at the output for ready impulses 17, the main gate 2 cannot be opened again by a start impulse following the stop impulse.

The gate circuit according to FIG. 3 differs from that according to FIG. 2 in that, instead of the start pulse gate 9, an "AND" gate 27 with a start pulse input 8 and two control inputs 25, 26 is used in conjunctive linkage, to which the two start pulse gate control multivibrators 10 and 22 are assigned. The closing input 12 of the start pulse control multivibrator 10 connected upstream of the control input 25 is connected to the output for main gate opening pulses 21 and the opening input 11 is connected to the output for reset pulses 18. The closing input of the other start pulse control multivibrator 24 is connected to the output for main gate closing pulses 16 while being Opening input 23 is connected to the output for readiness pulses 17. The "AND" gate 27 is also closed by the start pulse gate control multivibrator 10 during the opening switching reaction of the main gate control multivibrator 5. When the main gate closes, the other start impulse gate control multivibrator 22 is also tilted into the closed position by the main gate closure pulse emitted via the output for main gate closure pulses 16. The reset pulse appearing at the output for reset pulses 18 tilts the start pulse gate control multivibrator 10 into the open position and thus prepares the "AND" gate 27 for opening. The “AND” gate 27 is finally opened by the ready pulse appearing at the output for ready pulses 17 via the other start pulse gate control multivibrator 22 .

Claims (5)

Claims: 1. Circuit arrangement for a gate circuit for short switching times, consisting of a main gate with one or two associated main gate control multivibrators, an input for start pulses and an input for stop pulses and one between the input for start pulses and the opening input of a main gate control multivibrator Start pulse gate, to which one or two start pulse gate control multivibrators are assigned, and further consisting of a stop pulse gate arranged between the input for stop pulses and the closing input of a main gate control multivibrator, characterized in that the closing input of a start pulse gate control multivibrator (12) has a Output of a circuit unit provided for deriving switching pulses from the start pulses, for example an output for main gate opening pulses (21) of the one main gate control multivibrator or to the input for start pulses (8) . 2. Circuit arrangement for a gate circuit for short switching times according to claim 1, characterized in that the opening input of a start pulse gate control multivibrator (11) is connected to an output for readiness pulses (17). 3. Circuit arrangement for a gate circuit for short switching times according to claim 1, characterized in that an "AND" gate (27) with an input for start pulses (8) and two control inputs (25; 26) is used as the start pulse gate. 4. Circuit arrangement for a gate circuit - - according to claim 1 and 3, characterized in that _ the opening input (11) of the one control input (25) upstream of the start pulse gate control multivibrator (10) with the output for reset pulses (18) of a RücksteIlimpulsgebers (19 ) is connected and that the closing input (12) of the start pulse gate control multivibrator (10) is connected to the output for main gate opening pulses (21). 5. Circuit arrangement for a gate circuit according to claim 1, 3 and 4, characterized in that that the opening input of the other start pulse gate control multivibrator (23) with the output for readiness pulses (17) is in connection and that the closing input the other start pulse gate control multivibrator (24) with the output for main gate closing pulses connected is.