SU610221A1 - Current protection device - Google Patents

Description

(54) CURRENT CURRENT DEVICE

one

The invention relates to protection, control and signaling devices in various power sources, in particular, for powering the windings of electromagnets and electromagnetic clutches intended for electrophysical

instrumentation.

A current protection device is known that converts a direct current into a time interval containing a control trigger, a measuring circuit and a null organ 1.

The disadvantage of this device is the low accuracy of the differential value of the pulsating voltage.

Closest to the proposed current protection device, which responds to the current increment, contains a measuring unit connected via a control key with a storage element, the output of which is connected to the threshold unit, and two time elements 2.

This device does not allow to differentiate pulsed rapidly changing signals.

In order to solve functional possibilities, a synchronizer and a trigger are entered into the device, a memory element is made on the integrator, the direct and inverse inputs of which

connected to the measuring body via keys whose control inputs are connected to the trigger outputs, the first input of which is connected to the first output of the synchronizer, the second output of which is connected to the gate input of the threshold organ and through the time element to the second trigger input and the integrator input.

In order to increase noise immunity, the circuit is inputted from an eTchik, the control input of which is connected to the second time element on the one-oscillator, the input of which and the counting input of the trigger are connected to the output of the threshold organ.

Diagram of the device shown in the drawing.

The device contains a measuring body 1, keys. 2, 3, integrator 4 with a capacitor 5 and a reset circuit 6, threshold unit 7. one-shot 8, element 9, counter 10, and actuator 11. The circuit is controlled by synchronizer 12 with delay element 13 and control trigger 14.

Delayed clock pulse CHi switches trigger 14 and unlocks key 2. By the end of the period, the voltage at the integrator output is equal to the integral of the input value. Through the gap

a time equal to half the period of the first SI impulse of the Sig from the second output of the synchronizer 12 overturns the trigger 14, which locks the key 2 and unlocks the key 3, at the same time integrating the Iccros input voltage. By the time of arrival of CHi, the voltage at the integrator output is equal to the difference of the input voltage integrals. The difference voltage across the signal CHi is compared to the reference voltage in the threshold organ 7. After the delay time of the element 13, the integrator 4 is reset using circuit 6 and the trigger 14 is switched. Then the cycle repeats

If the differential voltage passes the reference voltage, at the time of the SI comparison, the signal from the threshold organ 7 goes to the one-shot 8, which through the HE9 element unlocks the Yuno counter of the counting input. The pulse duration of the one-shot 8 must be slightly longer than the duration of the period of the clock pulses. The needle pulse arriving at the one-shot 8 via the next CMi maintains the state of the one-shot and unlocked state of the counting input of the counter 10. The actuator 11 triggers only when the specified number of pulses arrives at the counter 10 with the frequency CHi. If at least one of the following second pulses is missing, the one-shot 8 returns to its original state and, having reset the counter 10, locks its input. Thus, with random single fluctuations in the measuring circuit, a disconnect signal does not occur.

Claims (2)

1. The device current protection, responsive to the current increment containing the measuring A body connected via a controllable key to a memory element, the output of which is connected to the threshold organ, and two elements of time, characterized in that, in order to expand the functionality, into it a synchronizer and a trigger are introduced; the storage element is made on the integrator, the direct and inverse inputs of which are connected to the measuring body via keys whose control inputs (5 are depressant with the trigger, per; (The YOU input is connected to the first output of the synchronizer, the second output of which is connected to the gate input of the threshold organ and through the time element to the second input of the trigger and the reset input of the integrator. 2. The device according to claim 1, characterized by, so that, in order to improve noise immunity, a counter is inserted into it, the control input of which is connected to the second time element on the one-channel, the input of the counter and the counting input Trggera connected to the output of the threshold organ. Sources of information taken into account. during examination: 1. Author's testimony of the USSR № 275113, cl. H 03 K 5/13, 1969. 2. USSR author's certificate number 267730, f cl. H 02 H 3/08, 1969..