SU1396095A1 - Device for checking insulation resistance of separated circuits - Google Patents

Abstract

The invention relates to measuring and control technology and can be used to automatically check disconnected relay switchgear devices, cable networks and other objects. The invention improves the reliability of monitoring the insulation resistance of disconnected circuits of various electronic and radio devices, which is achieved by applying two control modes at low and high test voltages, as well as by reducing the effect of the discharge current of the parasitic capacitance of the device on the controlled circuit. For this, the first 8-1 and second 8-2 keys and the second test voltage source 11 are additionally introduced into the device. The device also contains a relay-switching connector 1, resistors 2 and 6, memory block 3, decoder block 4, reference voltage source 5, comparator 7, control block 9, first test voltage source 10, test element 12 and control object 13 . 1 il. (L

Description

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The invention relates to instrumentation engineering and can be used to automatically test disconnected circuits of switching devices, cable networks, printed circuit boards, and other devices.

The aim of the invention is to increase the reliability of monitoring the insulation resistance of disconnected circuits of various electronic and radio devices by applying two control modes at 10 low and high test voltages.

The drawing shows a diagram of the device.

The device contains a relay-switching connector 1 (PKC), a resistor 2,. 3 memories, at first, enumeration of all block 3 of memory, block 4 of decoders, controlled circuits. The voltage source is controlled first from the source 11 with a low voltage rating. With a successful verification of all the measured circuits in the first stage, the control is conducted from the source 10 with a high voltage.

Consider two control modes.

1. There is no microdefect in the controlled circuit in the form of low-power resistance. The signal from the control unit 9 closes the switch 8-2, connected to the measuring circuit of the low-voltage test voltage source 11. The current in the measuring circuit is determined by the insulation resistance of the monitored section. In accordance with the program recorded in the block

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reference voltage source 5, resistor b, comparator 7, first 84 and second 8-2 keys, control unit 9, first 10 and second 11 sources of test voltage, And 12, control object 13 (OK).

The first output of control unit 9 is connected to the first input of the And 12 element, the second output is connected to the input of the memory block 3, the output of which is connected to the input of the 4 decoder unit, the first output of which is connected to the second input of the And 12 element, and the second output to the nepEibiM input relay switching connector 1, the second input of which is connected to the first terminal of the first resistor 6; The first output of the relay / switching connector 1 is connected to, "

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the first output of the second resistor 2 and the first input of the comparator 7, and the remaining outputs are connected to the terminals for connecting the test object, the second input of the comparator 7 is connected to the output of the source 5 of the reference voltage, and its output is connected to the third input of the And 12 element, the output of which is connected to the input of control block 9, the first terminals of the first I) and second 11 sources of test voltage are connected via the first 8-1 and second 8-2 keys to the second output of the first resistor 6, and the inputs of the first 8-1 and second 8-2 keys are connected to third and fourth respectively output control unit 9, the second terminal of the second resistor 2, the second terminals of the first 10 and second 11 springs test voltage and a second output 5 istonika reference voltage unit connected to a common bus.

The device works as follows.

The control program is recorded in block 3 jg of the memory. On command from block 9, power and clock pulses are supplied to the device blocks. The read control program from memory block 3 through the decoder block 4 enters the PKC block 1, providing a selection of the circuit to be monitored, and 55 to And 12, the second input of which receives the signal of the expected measurement result ().

The power supply is practically applied to the monitored section of the circuit. Before the same voltage, the parasitic capacitance of Spar is charged. In the absence of a microdefect, the current in the measuring circuit is obviously less than expected, therefore, at the output of comparator 7, a signal is formed that corresponds to the expected (). The polling signal from the control block 9 at the output of the And 12 element generates a "Norm signal allowing further testing. Upon successful verification from source 11, a transition is made to source 10. The test proceeds in the same way. The parasitic capacitance is charged to the corresponding high voltage. If at the first stage of testing, the signal "Norm is generated in the absence of microdefects, then at the second stage, if the insulation resistance value is not below the norm.

2. A microdefect is present in the monitored center. Assume that the insulation resistance test in the control object (OK) was successful. There is a microdefect of several ohms between the contacts of the tested circuit. In this case, the voltage at the last contact OK is half the voltage of the source 11, since the resistances of the resistors 6 and 2 are approximately equal. The parasitic capacitance Cp, p is discharged to the value at this contact, while the energy and discharge current are insufficient to burn the defect, but the current is sufficient to cause the comparator 7 to imbalance. Since the current in the measuring circuit does not correspond to the expected (), element 12 The polling signal does not work. The absence of the signal "The norm at the output of the element And 12 prohibits further verification. On the front panel of the console, flashing45

controlled circuit number and test number. According to this information, a defective circuit is found and the board is discarded.

Claims (2)

1. There is no microdefect in the controlled circuit in the form of low-power resistance. The signal from the control unit 9 closes the switch 8-2, connected to the measuring circuit of the low-voltage test voltage source 11. The current in the measuring circuit is determined by the insulation resistance of the monitored section. In accordance with the program recorded in the block 0 " five five g 5 The power supply is practically applied to the monitored section of the circuit. Before the same voltage, the parasitic capacitance of Spar is charged. In the absence of a microdefect, the current in the measuring circuit is obviously less than expected, therefore, at the output of comparator 7, a signal is formed that corresponds to the expected (). The polling signal from the control block 9 at the output of the And 12 element generates a "Norm signal allowing further testing. Upon successful verification from source 11, a transition is made to source 10. The test proceeds in the same way. The parasitic capacitance is charged to the corresponding high voltage. If at the first stage of testing, the signal "Norm is generated in the absence of microdefects, then at the second stage, if the insulation resistance value is not below the norm. 2. A microdefect is present in the monitored center. Assume that the insulation resistance test in the control object (OK) was successful. There is a microdefect of several ohms between the contacts of the tested circuit. In this case, the voltage on the last contact OK is half the voltage of source 11, since the resistances of resistors 6 and 2 are approximately equal. The parasitic capacitance Cp, p is discharged to the value at this contact, while the energy and discharge current are insufficient to burn the defect, but the current is sufficient to cause the comparator 7 to imbalance. Since the current in the measuring circuit does not correspond to the expected (), element 12 The polling signal does not work. The absence of the signal "The norm at the output of the element And 12 prohibits further verification. On the front panel of the console, flashing5 controlled circuit number and test number. According to this information, a defective circuit is found and the board is discarded. Invention Formula A device for monitoring the insulation resistance of disconnected circuits, comprising a control unit, an AND element, a memory unit. decoder unit, relay-switching connector, first and second resistors, reference voltage source, comparator, first test voltage source, the first output of the control unit is connected to the first input of the And element, the second output to the input of the memory block, the output of which connected to the input of the decoder unit, the first output of which is connected to the second input of the element I, and the second output to the first input of the relay-switching connector, the second input of which is connected to the first output of the first resistor, the first output of the relay the but-switching connector is connected to the first output of the second resistor and the first input of the comparator, and the remaining outputs are connected to the terminals for connecting the test object, the second input of the comparator is connected to the output of the reference voltage source, and its output is connected to the third input of the And element, the output which is connected to the input of the control unit, the second output of the second resistor, the first test voltage source, the second output of the reference voltage source is connected to a common bus, characterized in that Not the reliability of the control by reducing the effect of the discharge current of the parasitic capacitance of the device on the controlled circuit, the first and second keys and the second test voltage source are introduced into it, with the first terminals of the first and second test voltage sources being connected via the first and second keys to the second terminal the first resistor and the inputs of the first and second switches are connected respectively to the third and fourth outputs of the control unit; the second output of the second test voltage source is connected to the common a.