SU794564A1 - Pulse duration monitoring device - Google Patents

Description

one

The invention relates to the field of radio electronics and can be used in railway automation devices.

A device for controlling the pulse duration is known, comprising a pulse receiver, a clock pulse generator connected to a trigger counter, two triggers, and an output trigger 1.

A disadvantage of the known device is low noise immunity.

The aim of the invention is to improve the noise immunity of the device.

The goal is achieved by the fact that the device is equipped with two additional triggers, two delay lines and a trigger distributor, one input of which is directly, and the other through the first delay line connected to two outputs of a trigger counter, the third output of which is connected to the clock input of the first trigger, information the input of which is connected to the single input of the second trigger and to the inverse output of one additional trigger, which is connected via a second delay line to the single input another additional trigger, the output of which is connected to the input of the output trigger, and the clock input is connected to

one output of the trigger distributor, the other two outputs of which are connected respectively to the single input of the first trigger and to the information input

one additional trigger, the clock input of which is connected to the receiver output, and the single input to the output of the second trigger, whose information input is connected to the trigger input of the trigger

counter and with the direct output of one additional trigger, and the clock input is connected to another input of the clock distributor, the third input of which is connected to the input of the first trigger.

The drawing shows a block diagram of the device.

The device contains a generator 1 clock pulses connected to the trigger

counter 2, the first delay line 3, the trigger distributor 4 connected to the first trigger 5, the second trigger 6, one additional trigger 7 connected to the receiver 8 and the second delay line 9, which in turn is connected to another additional trigger 10, the output of which connected to the output trigger 11. The device operates as follows.

The signal from the output of the receiver 8 enters the clock input of the trigger 7 and switches it from the state “1 to the state” O, since the information input of the trigger 7 receives the signal “O from the output of the trigger distributor 4. The trigger 7 turns on and removes the prohibition from the input of the installation in the unit of the trigger 6 and 10 and changes the signal at the information input of the trigger 5 from "O to" 1. The signal “O from the direct output of the trigger 7 arrives at the information input of the trigger 6, preparing it for switching, and to the reset input of the trigger counter 2. If at this moment the trigger 5 is not turned on, the signal from the output of the trigger counter 2 goes through the line 3 3 to the clock inputs of the trigger distributor 4 and trigger 6, turns on trigger 6, because the off state of trigger 5 does not allow the trigger distributor 4 to turn on. TpHrj ep 6, when turned on, sends a signal "O to the single trigger input 7 and turns it off, this The signal "O from the inverted output of trigger 7 arrives at the information input of trigger 5 and to the single input of trigger 6 and switches it to the initial state, which in turn removes the prohibition from trigger 7. The signal from the direct output of trigger 7 removes the prohibition from the trigger counter 2. Consequently, at this moment the device is in the initial state and the trigger counter 2 begins to count the pulses of the generator 1, i.e. the arrival of the signal from the receiver 8 is practically the beginning of the measurement of the duration of the period of the output signal of the receiver 8.

If the period of the output signal of the receiver 8 is within the specified limits, then the trigger counter 2 counts the required number of pulses from generator 1, and the signal from the output of counter 2 turns on trigger 5, which in turn removes the trigger of the trigger distributor 4. Receipt from the output of the receiver 8 to the clock input of the trigger 7 of the new pulse, announcing the end of the studied period, switches it. Switching trigger 7 removes the prohibition from triggers 6 and 10 and prepares trigger 6 for switching on the information input and sends an “O signal” to the reset input of trigger trigger 2.

As a result, the outputs of the trigger counter 2 receive signals, one of which turns on the trigger distributor 4, and the other through the first delay line 3 and the trigger distributor 4 enters the single input of the trigger 5 and turns it off. Turning off the trigger 5 in turn switches the trigger distributor 4 to its initial state than

the prohibition is removed from the single input of trigger 5.

In addition, the signal from the output of the first delay line 3 arrives at the clock input of the trigger 6 and turns it on. Trigger 6, when turned on, turns off trigger 7, the shutdown of which leads to the removal of the prohibition from the reset input of trigger meter 2 and the switching off of trigger 6, and also prepares trigger 5 for a new switch-on and turns off trigger 10. Turning off trigger 10 causes switching the output trigger I. Frequency switching output

trigger 11 is equal to the frequency of the signal at the output of the receiver 8.

If the period of the signal from receiver output 8 is longer than the nominal time, then after trigger counter 2 counts a certain number of generator 1 pulses and turns on trigger 5, counter 2 continues to count generator 1 pulses and as a result, at the output of counter 2, a signal appears that includes trigger valve 4. Since trigger valve 4 is turned on before trigger 7 is activated, switching it on does not switch trigger 10, since the "On prohibit from trigger 7" signal is present at its single input.

After the trigger distributor 4 is turned on, the trigger counter 2 will continue to count the generator 1 pulses, but the state of the device elements will not change until the new pulse starts at the trigger input 7, after which all elements of the device will return to the initial state and the next signal will start measuring receiver output 8, and

since the fourth trigger 10 did not switch, the output trigger 11 did not switch either.

If the output trigger 11 does not switch, it indicates that the period of the output signal of the receiver 8 is greater than or less than the nominal period of the period of the signal under study, or the device is faulty. If the output trigger 11 is switched, this indicates that the device is working properly and the parameters of the signal under investigation are within the specified limits.

The use of the invention improves the selectivity of the device.

Claims (1)

1. Copyright certificate № 389487, cl. G 04F 10/04, 1970.