SU1274024A1 - Device for checking serviceability of n fuses - Google Patents

Abstract

The invention relates to electrical engineering, in particular for controlling fuses. The purpose of the invention is to simplify and increase reliability. When any of the fuses blows, the amplitude of the corresponding pulses is greater than the voltage of the threshold of the comparator 18, but less than the threshold of the comparator 17. The comparator 18 is triggered to ensure that the key 23 is closed and the indicator 25 is energized. The latter flashes the number of the prehater according to the parallel code, arriving at the inputs of the indicator 25 from the outputs of the decoder 8. From the additional output 51 at the time the comparator 18 is triggered, the signal can be cleared to turn off the sound alarms. The possibility of observing failures of several fuses is provided in the device by decreasing (L of the frequency of the generator 9 according to the output signal of the comparator 18. 1 Cp fsly, 2 ill.

Description

The invention relates to electrical engineering and is intended for use in equipment built-in control fuses in DC and AC circuits.

The purpose of the invention is to simplify and increase the reliability of the device by reducing the number of pulse transformers, increasing the reliability of the device in fuse chains with a capacitive nature of the load by forming the selective conductivity of the two-pole network.

FIG. a diagram of the device for monitoring the health of fuses; in fig. 2 - voltage diagrams for his work.

The device contains in the control circuit of each fuse 1 pulse transformer 2, the primary winding 3 of which through the two-terminal switch 4 is connected to the first terminal 6 of the fuse to be monitored by the first terminal 5, (n + 1) channel switch 7, the decoder 8, the first pulse generator 9 and the binary the counter 10, the outputs 11 bits; connected to the control inputs 12 of the switch and the inputs 13 of the decoder, and the counting input 14 to the output 15 of the first pulse generator. The device has a second pulse generator 16, the first 17 and the second 18 comparators, a two-level source 19 of reference voltages with the first 20 and second 21 outputs, a two-input element 22 And, a switch 23, a resistor 24 and a digital indicator 25 The second output 26 of the primary winding 3 of the pulse transformer 2 is connected to the second output 27 of the monitored fuse directly, the first output 28 of the secondary winding 29 to the common power supply wire 30, and the second output 31 to the output of one of the channels of the switch 7, the output of the (n + 1) -th channel of which is connected to the bus 32 pit no. The inputs of all channels of the switch 7 are combined and connected to the first inputs 33 and 34 of the first 17 and second 18 comparators directly and to the external element 22 And through a resistor 24. The second inputs 35 and 36 of the first 17 and second 18 comparators are connected to the first 20 and second 21 outputs source 19

reference stresses, respectively. The output 37 of the first comparator 17 is connected to the reset input 38 of the counter 10, and the output 39 of the second comparator 18 is connected to the control input 40 of the key 23 and to the control input 41 of the first generator 9 pulses, the inputs 43 of the digital indicator 25 are connected to the outputs 42 of the decoder 8. The power input 44 of which is connected via a switch 23 to the power bus 32, the first input 45 of the element 22 And is connected to the output 15 of the first generator 9 of pulses, and the second input 46 to the output 47 of the second generator 16 of pulses. The bipolar switch 4 is made in the form of a series-connected diode 48 and a resistor 49 shunt by a capacitor 50. The generators 9 and 6 of the pulses can be made according to the same scheme. The frequency f of the generator 9 is selected based on the convenience of visual perception of the signal by the operator, and the frequency f of the generator 16 is selected according to the ratio f 1 Of. Additional output 51 of the device is designed to turn on the audio alarm.

The device works as follows.

After turning on the power, the generator 9 forms a sequence of rectangular pulses with a frequency f (Fig. 2c () and the generator 16 forms a sequence of rectangular pulses with a frequency f (Fig. 2,}). Through element 22 And and the resistor 24 packs of pulses (Fig. 2 , b) arrive at the combined inputs of the switch channels

7, as well as the inputs 33 and 34 of the comparators 17 and 18. The pulses from the output 15 of the generator 9 are fed to the counting input 14 of the counter 10, the outputs of the 11 bits of which generate a parallel code to the control inputs 12 of the switch 7 and to the inputs 13 decoder 8. Switch 7 on the output signals of the counter 10 provides alternate connection

Claims (2)

0 secondary windings 29 of transformers 2 to the output of element 22 I. The amplitude of the pulses Ujj at the input of the switch 7 and at the inputs 33 and 34 of the comparators I7 and 18 depends on the state of the fuse in the primary winding 3 respectively. of the transformer 2. If all the fuses are good, then the amplitude of the pulses Ujj will be less than the threshold voltages of the first 1 and 7 second comparators when controlling all 1, .., n fuses, and when the (+ 1) switch of the switch is connected the amplitude is maximum and exceeds the voltage of the trigger threshold U, the first comparator 17 (Fig. 2.6). The latter triggers and resets the 1O counter to the initial state for a new fuse polling cycle. When any of the fuses blows, the amplitude of the corresponding pulses U is greater than the voltage threshold of the second comparator 18, but less than the voltage and the other threshold of the first comparator 17 (Figs.2.2-). The comparator 18 operates by providing the key 23 and supplying power to the indicator 25. The latter flashes the number of the blown fuse in accordance with the parallel code sent to the indicator inputs 25 from the decoder outputs 8. Additional output 51 can trigger the output of the comparator 18 t signal to activate the alarm. The possibility of observing failures of several fuses is provided in the device by reducing the frequency of the first generator 9 by the output signal of the second comparator 18. In this case, in the absence of defective fuses, the frequency of the generator 9 is maximum. When the first fault appears, the comparator 18 is triggered and provides a reduction in the frequency of the generator 9, which improves the condition of displaying the indicator on the indicator when the next several defective fuses, the numbers of which are displayed with a lower frequency, appear. The positive effect is to simplify and increase the reliability of the device by halving the number of pulse transformers, while reducing size and cost. device device In addition, it provides reliable control of fuses in DC and AC circuits with capacitive load, which expands the scope of application of the device. Claims. A device for monitoring the operability of p fuses, which contains a pulse transformer in the control circuit of each fuse, the primary winding of which is connected to the first output of the monitored fuse through a connecting two-pole device, a n-1 switch, a decoder, a first pulse generator and a binary counter, outputs of bits connected to control inputs of the switch and inputs of the decoder, and the counting input to the output of the first pulse generator, characterized in that, in order to simplify and increase reliability by reducing the number of pulsed transformers, a second pulse generator, the first and second comparators are a two-level source of reference voltages with the first and second outputs, a two-input element And, a key, a resistor and a digital indicator, with the second output of the primary winding of each pulse the transformer is connected to the second output of the monitored fuse directly, the first output of the secondary winding is connected to the common power wire, and the second output is connected to the output of one of the n channels mutator, the output of (n + 1) -th channel of which is connected to the power bus, the inputs of all switch channels are combined and connected to the first inputs of the first and second comparators directly and to the output of the And element via a resistor, the second inputs of the first and second comparators are connected to the first and the second output of the reference voltage source, respectively, the output of the first comparator is connected to the reset input of the counter, and the output of the second comparator to the control input of the key and to the control input of the first pulse generator, to the outputs of the decoder The inputs of the digital indicator are connected, the power input of which is connected via a switch to the power bus, the first input of the I element is connected to the output of the first one, and the second input is connected to the output of the second pulse generator. 2. The device according to claim 1, which is designed so that, in order to increase the reliability of work in the circuits of the fuses with a capacitive character of the load, by forming the selective conductance of the discharge 5127402А6 a two-pole device, the last one is a diode and a resistor, is shunty filled in the form of a series-connected capacitor. "22 Unpf.l pi % U.nof, 1 Inor.2 P + 1 fpa2.2 g t P P