JPS6089765A - Slide noise detector - Google Patents

Abstract

PURPOSE:To confirm continuously a contact state by counting the frequency of generation of an abnormal voltage higher than a specific value at the slider of a variable resistor when the slider is moved. CONSTITUTION:The one resistor and sliding terminal of the variable resistor 10 to be checked are connected to a constant current source 4. A counter 5 counts an abnormal voltage value in case of a contacting defect between the resistor and sliding terminal of the resistor 10. The varying voltage counted by the counter 5 is displayed on a display device 8 through a driver 6. An ohmmeter 1 measures the resistance value of the inspected resistance and the output value of a constasnt current source 4 is set through a gate circuit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding noise detection device that counts and detects sliding noise between a potentiometer and a variable resistor.

Generally speaking, the sliding noise of a variable resistor can be solved by flowing a constant current from the resistor to the sliding contact, and then moving the sliding contact over the resistor. This can be confirmed by detecting abnormal voltage that occurs between the contacts. Furthermore, if a contact failure occurs in the sliding body, the contact resistance becomes infinite, so the contact state can be continuously checked.

Conventionally, this type of sliding noise has been measured by moving the resistor and the sliding surface and recording the abnormal pressure generated between the resistor and the sliding surface on an X-Y recorder, or by The method used was to use a synchroscope and check on the screen of the synchroscope. However, in these methods, the distance between the resistor and the sliding contact is several μsec or several IQ n5e.
If a contact failure occurs in the time width c, there is a drawback that it cannot be confirmed on an X=Y recorder or with a synchroscope. Furthermore, even when the sliding contact is fixed and a vibration test is performed, it is impossible to detect contact failure in the above-mentioned time range, and furthermore, sliding noise is detected; There was also the problem of having to prepare expensive measuring instruments such as recorders and synchroscopes.

The purpose of the present invention is to provide a sliding noise detection device that solves the above-mentioned table problems, can detect short-term contact failures of variable resistors, etc., and can easily confirm the status of failures. be.

The sliding noise detection device M of the present invention includes a constant current source that supplies a constant current between one terminal of a resistor of a variable resistor to be measured and a slider, and when the slider is moved. The slider includes a counting circuit that detects only the abnormal voltage generated in the slider and counts the number of times the abnormal voltage occurs, and a display circuit that displays the sliding noise of the counting circuit.

According to the present invention, it is possible to display abnormal voltage due to a short contact failure of several microseconds to several tens of nanoseconds on the display simply by pressing the start switch and varying the sliding contact. You can check whether the variable resistor is good or not just by checking the (・).

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram of a resistance measurement system including an embodiment of the present invention. In this example, the constant current value can be controlled externally.
Constant current power supply 4. The variable resistor 10 to be tested and the ohmmeter 1 are connected in series from the (g) output terminal of the constant current power supply 4 to one terminal of the resistor of the variable resistor 10 to be tested, and the resistance of this resistor is connected in series. Both parts are connected to the input terminal of ohmmeter 1. The sliding terminal of this variable resistor 10 is connected to the (→ output terminal) of the constant current power supply 4.Next, the abnormal voltage value at the time of poor contact that occurs between the resistor of the variable resistor 10 and the sliding terminal is For counting, the other terminal of the resistor is connected to the input terminal of a counter 5, and the output terminal of this counter 5 is connected to the input terminal of a driver circuit 6 for driving the display tube. The output terminal of is connected to the input terminal of the display tube 8.

The switch 7 is used to give a start command to the ohmmeter 1, and outputs a 4-bit, 5-digit signal representing a resistance value from the output terminal of the ohmmeter 1. The terminal of this ohmmeter 1 is connected to the input terminal of each gate circuit 3 for setting a constant current according to the resistance value, and the output terminal representing the unit is connected to a decoder 2 for converting a binary number into a decimal number. connected to the input terminal of The output terminal of this decoder 2 is connected to the opening/closing input terminal of each gate circuit 30 input terminal in order to select only one of each gate circuit 3. The outputs of the gate circuits 3 are respectively connected to a control section of a constant current power source 4 for setting a constant current corresponding to the resistance value, and constitute a sliding noise detection and display circuit.

Next, the operation of this embodiment will be explained. here - as an example]
1 (Suppose we want to detect an ohm variable resistor. First,
By pressing the start switch 7, the ohmmeter 1 starts measuring to measure the resistance value of the test resistor, approximately 5
After 00m5ec, the measurement results are digitized and outputted at the same time as the unit. Since the total resistance value of this variable resistor is 1 to ohm, a total of 1 will display 1000, and the output will be output as is in the BCD code, and as a unit of ohm, the BCD signal will be a 1-digit, 4-bit signal. The ones digit is output. The output resistance values are input to five gate circuits 3, each corresponding to a five-digit BCD code. In the 5-digit BCD code from ohmmeter 1, only the 10'' digit is ``1'' and all other digits are ``0''. A signal is input to the circuit 3. The code representing the unit is "1"
The output signal of the digit is input as is to the decoder 2, converted into a decimal number by the decoder 2, and the decoder 2 outputs "1".

The signal representing this unit is one of the five gate circuits 3.
The digits 1f to 103 are input in parallel as signals for opening the four gate circuits 3. The gate circuit 3 for the other 104 digit is shown to be opened only when a code whose unit is kilo ohm is output. Therefore, the gate circuit 3 has a 1 digit signal in the 10 digit. The decoder 2 inputs the gate circuit open signal to the four digits 10 to ]0, and the 1()3 digit indicates the resistance value from the ohmmeter 1 to the gate 103 digit. A signal is emitted only to the output of circuit 3.

This signal is sent to the current setting control section of the constant current power source 4 in order to set the constant current of the constant current power source 4 to 10 mA. In addition, in order to keep the fluctuating voltage value for detecting sliding noise constant even if the test resistance value changes, five gate circuits 3 are used to set a constant current corresponding to the resistance value. 'C constant current value is controlled.

The set voltage of the constant current power supply 4 is TTLL/bell, 5 mm, and the contact resistance is about 1 round of the test resistance value.

Since this test resistance value is 11 (ohms), the contact resistance is about 10 ohms, and by setting a constant current of 10 mA, a fluctuating voltage of about 0.1 mm is generated. By moving the child, a contact failure can be confirmed.If a contact failure occurs, an abnormal voltage waveform as shown in A in FIG. 2 will be generated.

The counter 5 counts d1 only when this abnormal voltage A reaches the threshold of the TTL level. This counter 5 is
It starts counting from 0, has a binary 12-bit V register, and has the function of counting up to 100. Counted fluctuating voltage A
is input from the output of the counter 5 to the driver 6 for driving the display tube, and the counted value is displayed by the display tube 8.

As explained above, when the test resistance value is 100 ohms, the constant current value is set to 100 mA, and when the test resistance value is 10 ohms, the constant current value is set to 1 mA to keep the fluctuating voltage constant. It is also possible to maintain the voltage fluctuation at the TTL level at the time of contact failure, making it possible to test any resistance value.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a resistance measurement system including an embodiment of the present invention, and FIG. 2 is a waveform diagram of a fluctuating voltage for detecting sliding noise in FIG. 1. In the figure, 1: Ohmmeter, 2: Decoder, 3: Gate circuit, 4: Constant current power supply, Counter: , 6... Driver, 7... Switch, 8...
...display tube.

Claims (1)

[Claims] A constant current source that supplies a constant current between one terminal of the resistor of the variable resistor to be measured and the slider, and a predetermined voltage generated in the slider when the slider is moved. A sliding noise detection device that includes a counting circuit that detects only the above abnormal voltage and counts the number of times the abnormal voltage occurs, and a display circuit that displays the sliding noise of the counting circuit.