SU1422264A1 - Indicator of burnt fusible cutouts - Google Patents

Abstract

The invention relates to electrical engineering and is intended for use in power supply systems containing a large number of fuses. The aim of the invention is to increase reliability. The goal is achieved by introducing into the device a multiplexer 3 whose output is connected to the inputs of the switches 4, 5. The output of the pulse generator 6 is connected to elements I. The output of the second decoder is connected to the gate by the input of the decoder 9. The decoder is connected to digital indicators. The device provides an indication of the numbers of blown fuses, as well as the number of these fuses. 1. il.

Description

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The invention relates to electrical engineering and is intended for use in power supply systems containing a large number of fuses.

The purpose of the invention is to increase reliability by providing an indication of the out of order fuses.

: The drawing shows the proposed: unit |

i The device monitors the protection of Tsiteli 1 of loads 2 and contains a select- TJop-multiplexer 3, the inverse output of which is connected to the inputs of the first 4 and second 5 switches. The output of the generator 6 pulses is connected to the first 7 and second 8 And elements, the inverse input of the first element And 7, and the second input of the second element And 8 are connected to the second output of the switch 5 connected to the counterblock input of the decoder 9 connected to the digital indicators 10.

 The output of the first element And 7 sub- Key n to the input of the element OR 11, the second input through the counter 12 is connected to the output of the second element And 8. The output of the element OR 11 is connected to the counting input of the binary counter 13, S-input of the selector-multiplexer 3 and the second input the first switch 4, the output of the binary counter is connected to the address input of the selector-multiplexer 3, zero input - to the R-input of the binary-decimal counter 14, output 2 - to the first input of the second switch 5. The output of the first switch 4 is connected to the counting input of the binary decimal counter 14, the output of which is connected to the inputs of the decoder 9, the control inputs of the switches 4 and 5, and also R — the input of the binary counter 13 via the trimming circuit 15 is connected to an additional power source.

The device for indication of blown fuses works as follows.

In the main mode - the mode of indication of the number of blown fuses at the control input of the REQUEST device and at the control inputs of the first 4 and second 5 switches connected to it there is a potential O. At the same time, the signals pass from the first inputs.

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The generator 6 generates r clock pulses, which through the first element AND 7 and the element OR 11 arrive at the counting input of the binary counter.

13, on the outputs of which an address is formed on the selector-multiplexer 3. Thus, with the drive of each clock pulse, the inputs of the multiplexer 3 are alternately switched on.

During normal operation of power supplies and intact fuses 1, the potentials 1 are present at the inputs of multiplexer 3, and the potential O at the inverse output is independent of the binary counter 13 state. Consequently, the binary input counter 14 connected through the first switch 4 with the inverse output of multiplexer 3, the pulses do not arrive. At the beginning of each polling cycle at the target state of the binary counter 13 from its zero output to the zero-reset input of the binary-decimal counter 14 A pulse arrives that sets it to the zero state, and at the end of the polling cycle when the binary counter 13 is filled with its output 2 through the second switch 5, an overflow pulse is sent to the gate of the decoder of the binary-decimal code (seven-segment code), connecting the digital seven-segment indicators 10. Since the information inputs of the decoder 9 are connected to the binary outputs but-decimal counter

14, being in the zero state, zeroes are displayed on the indicators. Simultaneously, the overflow pulse arrives at the inverting input of the first 7 and at the second input of the second 8 elements I. Thus, the passage of clock pulses to the binary input counter through the first element AND 7 and the element OR 11 stops, and through the second element 8 begins filling counter 12. So. Thus, at the time of filling the counter 12, the device operates in indication of the contents of the binary-decimal counter 14. The counter 12 is selected based on the selected clock frequency and the required display time.

After filling the counter 12 from its output, the overflow pulse through the element OR 11 enters the counting input of the binary counter 13, and begins

is a new polling cycle. In the event of a failure of any power sources or blown fuses t, the potentials O appear on the corresponding inputs of the multiplexer, and the inverse output when the address code coincides with the number of the failed channel is a positive pulse, which through the first switch 4 goes to the counting input binary decimal counter 14. Thus, in one polling cycle, the number of blown fuses is counted and indicated for a time equal to the counter filling time.

If necessary, the operator, on the basis of the indicator readings, makes a decision on the expediency or inexpediency of restoring the power sources, and if necessary, turns on the Query of blown fuses mode.

At the same time, potential 1 is supplied to the control input of the INQUIRY device and control inputs connected to it. The signals through the switches pass from the second inputs. At the same time a differentiating circuit consisting of a capacitor and a resistor 15 organizes a short a positive pulse, acting on the zero input of the binary counter 13 and nulling it. The binary-decimal counter is also zeroed.

Clock pulses from the generator 6 through the first element AND 7 and the element OR 11 are fed to the counting input of the binary counter 13 and through the first switch 4 to the counting input of the binary-decimal counter 14. In this case, the binary counter provides alternate switching of the multiplexer inputs The partial counter 14 forms the binary-decimal number of the included input. As soon as the channel is turned on with a potential O at the input (a fuse has blown or a power source is faulty), potential 1 appears at the inverse output of multiplexer 3, which through the second switch 5 goes to the gate input of the decoder 9 and turns on the indicators 10. On which the number is displayed failed .. fuse (power supply), formed. in a binary-ten-meter counter 14. At the same time, the potential

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1 enters the inverting input of the first element And 7 and the second input of the second element And 8, the clock passes through the first element And 7 stops, the counters 13 and 14 stop, and the second element And 6 starts filling the counter 12. After filling the last one with it In the event of an overflow pulse through the OR element 11, it arrives at the counting inputs of counters 13 and 14 and the switching of the multiplexer inputs continues until the next faulty channel. The time of indication of the number of the blown fuse is determined by the filling time of the counter 12. If all the fuses and power sources are intact, the interrogation is performed non-stop and the indicators remain on.

The proposed device can be implemented on standard integrated circuits, for example, selector-multiplexer 133 KP 7, decoder 514 ID 1, binary counter 133 NOT 7, binary-decimal counter 133 IE 6.

The proposed device, in comparison with the known one, possesses wider functional capabilities by providing an indication of the number of failed fuses, which is advisable for analyzing when restoring the system and deciding whether to restore the fuses or switch over the reserve set.

Claims (1)

Claims. A device for indicating blown fuses, containing a decoder, the output of which is connected to the input of a digital indicator, two AND logic gates, one OR logic element, a pulse generator, and a counter that is different in order to increase the reliability by providing an indication of the number of fuses, a selector-multiplexer, two switches, binary-decimal and binary counters, differentiating the chain, with the information inputs of the selector-multiplexer connecting Nena with terminals for connecting the load-side fuses and inversnsh output Perg vym input of the first and second input The second switch, the output of the pulse generator is connected to the first inputs of the first and second elements And; the inverse input of the first element And the second input of the second element And connected to the output of the second switch connected to the gate of the decoder, the output of the first element And connected to the first input of the control panel, the second input of which through the counter is connected to the output of the second element And, output the OR element is connected to the CQ counting input of the binary counter, the 3 input of the selector-multiplexer and the second input of the first switch, the output of the binary counter is connected to address selector-multiplexer input, zero output - to R-input of a binary-decimal counter, output 2 - to the first input of a second switch, the output of the first switch is connected to the counting input of a binary-decimal counter, the output of which is connected to digital inputs of the decoder, control - switching inputs of switches that control the 1 output of the REQUEST element are connected via a capacitor of a differentiating RC circuit to the R input of a binary counter, to which an additional source is connected via a resistor of the same differentiation circuit Itai.