JPH0829461A - Electrical performance tester - Google Patents

Abstract

PURPOSE:To provide an electrical performance tester which makes both a resistance value and a current value visible during measurement. CONSTITUTION:The current range selecting circuit 32 of a range selecting switch 10 and a measuring circuit 33 are connected to a current source circuit connected to a DC power source circuit 30 via a polarity changeover switch 11. A resistance 34 to be tested is interposed in series in the measuring circuit 33. A voltage measuring circuit 35 measures voltages at both ends of the resistance 34 to be tested. A current detecting circuit 36 detects current flowing through the measuring circuit 33. The resistance range selecting circuit 38 of the range selecting switch 10 is connected to the current detecting circuit 36. A measured voltage value and a detected current value are input to an arithmetic circuit 39, and a resistance value of the resistance 34 to be tested is computed and displayed in a digital display 6. The detected current value is displayed by a digital display 7. A predetermined combination of the resistance range and the current range can be selected and set by the range selecting switch 10 by a single operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures and displays the contact resistance of mechanical contacts such as relays and the resistance values of elements and circuits mounted on an IC substrate, and also displays the test current value flowing in the measuring circuit. The present invention relates to an electrical performance tester capable of detecting and displaying, and further supplying electric power for an operation test of a relay or the like.

[0002]

2. Description of the Related Art Conventionally, low resistance measuring instruments for measuring contact resistances of various switches and relay contacts used in electronic equipment explicitly indicate a test current to be supplied to a measuring circuit during resistance measurement. It did not have the function to switch. Further, it does not have a function of displaying only the resistance value at the time of measurement and simultaneously displaying the value of the current flowing in the measurement circuit. For this reason, the resistance value and the current value at the time of measurement cannot be visually recognized at the same time, and an accurate electrical performance test cannot be performed.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide an electrical performance tester capable of simultaneously visually recognizing a resistance value and a current value during measurement. To do.

[0004]

In order to achieve the above object, the electrical performance tester of the present invention according to claim 1 is a current source circuit connected to a DC power supply circuit through a polarity change switch, and A measurement circuit connected to the current source circuit, a voltage measurement circuit for measuring the voltage across the test resistor interposed in the measurement circuit, a current detection circuit for detecting the current flowing in the measurement circuit by a current sensor, and An arithmetic circuit that calculates the resistance value of the sample resistance based on the measurement value of the voltage measurement circuit and the detection value of the current detection circuit, and a digital display that displays the current detection value and the calculated resistance value, respectively. And a range selection switch capable of selecting a predetermined combination of a current range given to the current source circuit and a resistance range given to the current detection circuit with one touch.

According to a second aspect of the present invention, there is provided an electrical performance tester according to the first aspect of the invention, wherein the voltage setting switch, the DC / AC changeover switch, and the oscillator are provided. And a power supply circuit including a voltage / power amplifier.

[0006]

ACTION AND EFFECT OF THE INVENTION The action and effect of the electrical performance tester 1 described in claim 1 are as follows. The range selection switch 10 selects the current range given to the current source circuit 31 and the resistance range given to the current detection circuit 36. The current range and the polarity changeover switch 11 determine the test current and the current direction to be supplied from the current source circuit 31 to the measurement circuit 33, that is, the test resistor 34, and the resistance range is the test sample provided in the measurement circuit 33. The maximum value of the resistance for measuring the resistance 34 is determined. The voltage measuring circuit 35 measures the voltage across the resistance under test, and the current detecting circuit 36 detects the current flowing through the measuring circuit 33. The measured voltage value and the detected current value are input to the arithmetic circuit 39, and the calculated resistance value of the test resistor 34 and the detected current value are displayed together on the digital display. As shown in FIG. 1, the combination of the current range and the resistance range is arranged so that they can be visually distinguished easily at the same time, so that the range selection switch 10 can be selected with one touch. The resistance value of the sample resistor 34 and the detected current value can be confirmed by the digital indicators 6 and 7 on the front panel 5. Therefore, the present invention has an effect that it is possible to provide an excellent electrical performance tester capable of simultaneously visually recognizing a resistance value and a current value at the time of measurement.

According to the electrical performance tester of the second aspect, since the power supply circuit 50 is provided, the performance test can be performed by operating the relay even if there is a power outage due to a reason such as during construction. There is an effect that the convenience can be further enhanced.

[0008]

Embodiments of the present invention will be described with reference to the accompanying drawings. As shown in the front view of FIG. 1, an electrical performance tester (hereinafter referred to as a tester) 1 according to the present invention has a casing 2 on which both sides 3 and 3'have handles 4 for carrying which can be rotated. ing. The handle 4 also serves as a support leg that supports the front side of the tester 1 during the test. Digital indicators 6 and 7 for simultaneously displaying the calculated resistance value and the detected current value, which are the main parts of the tester 1, are arranged substantially at the center of the front panel 5. On the right side of the digital indicators 6 and 7, there are arranged a zero point adjustment knob 8 having a lock mechanism, a current fine adjustment knob 9, a range selection switch 10 and a polarity changing switch 11. Reference numeral 12 is a connection terminal to which a probe (not shown) provided with a pair of measuring elements is connected. Further, on the left side of the indicators 6 and 7, there are arranged a voltage setting switch 13 and an output terminal 14 for switching the AC / DC for the power supply circuit 50 attached to the tester 1 and setting the output voltage. There is.

The range selection switch 10 includes a resistance range indicator 15 marked 20 ohms, 2 ohms, 200 milliohms and 20 milliohms in the horizontal direction and 10 in the vertical direction.
Eight selection switches 10a to 10h are arranged in a cluster in correspondence with the current range display 16 labeled as 00 mA, 100 mA, and 10 mA. For example, by pressing the selection switch 10a, a resistance range of 2 ohms and a current range of 1000 mA can be selectively set with one touch. In the same manner, by pressing any of the selection switches 10b to 10h, the display 15 of the resistance range in the horizontal direction and the display 1 of the current range in the vertical direction are displayed.
The resistance range and the current range of the combination corresponding to 6 are selected and set with one touch.

Further, the voltage setting switch 13 has an AC / DC display 17 written horizontally as AC (AC) and DC (DC), and an output voltage display vertically labeled as 100V, 48V and 24V. Corresponding to No. 18, six switches 13a to 13f are arranged in a cluster. By pressing the switch 13a, 100 V AC can be supplied from the output terminal 14. Similarly, by pressing any of the switches 13b to 13f in the same manner, the lateral alternating current
A combination of power supplies corresponding to the DC display 17 and the vertical output voltage display 18 is supplied.

FIG. 2 shows a schematic block diagram of the tester 1. 30 is a DC power supply circuit, 31 is a polarity changing switch 11
A current source circuit (for example, 4.8V, 1A) connected to the DC power supply circuit 30 via a current range selection circuit 32 and a measurement circuit 33 of the range selection switch 10. The polarity conversion switch 11 switches the current direction of the current source circuit 31 supplied to the measuring circuit 33. A test resistor 34 is inserted in series with the measuring circuit 33. 35 is a voltage measuring circuit for measuring the voltage across the resistor under test 34, 36 is the current flowing through the measuring circuit 33,
It is a current detection circuit that is detected by the current sensor 37 including a Hall element or the like. A resistance range selection circuit 38 of the range selection switch 10 is connected to the current detection circuit 36.

The measured value of the voltage measuring circuit 35 and the detected value of the current detecting circuit 36 are respectively inputted to the arithmetic circuit 39, and the resistance value of the sample resistor 34 is calculated by the equation R = V / I. . The calculated value is input to the display drive circuit 40 and displayed on the digital display 6. Further, the detection value of the current detection circuit 36 is input to the display drive circuit 41 and displayed by the digital display 7.

Reference numeral 50 is a power supply circuit attached to the tester 1, and comprises a voltage setting switch 13, an oscillator 51, and a voltage / power amplifier 52. This power supply circuit 50
Is operated by pressing the arbitrary voltage setting switches 13a to 13f of the DC power supply of the DC power supply circuit 30.
In addition, the voltage / power amplifier 52 is used to convert the voltage into an alternating current or a direct current of a predetermined voltage and supply it from the output terminal 14.

FIG. 3 is a circuit diagram of the range selection switch 10, wherein the selection switches 10a to 10h are connected to a current range selection circuit 32 and a resistance range selection circuit 38. By pressing the selection switches 10a-10h, resistance ranges 20 ohms, 2 ohms, 200 milliohms and 20 milliohms and current ranges 1000 mA, 1
A predetermined combination of 00 mA and 10 mA can be selected and set with one touch.

The tester 1 having the above-mentioned structure is used for measuring various switches such as a toggle switch, a rotary switch, and a slide switch having mechanical contacts used in electronic equipment, and a contact resistance of a small relay for control, etc.
Amperometric method according to 441 standard (by direct current), low voltage,
It is possible to carry out electrical performance tests such as the low current method (using direct current). At the time of this measurement, the range selection switch 10
The combination of a predetermined resistance range and current range can be selected and set with one touch using the selection switches 10a to 10h, and the current value flowing through the measurement circuit 33, that is, the sample resistance 34 as well as the measured resistance value is digitally displayed. Can be displayed. Further, in the measurement by the voltage drop method specified in JIS, if the actual energized current value is different from the rated test current, the current fine adjustment knob 9 can be used to adjust to the specified current, so an accurate measurement test can be performed. Can be implemented. Furthermore, the power supply circuit 5
Since 0 is provided, there is an advantage that inspection involving operation of a relay or the like can be performed even at the time of power failure.

[Brief description of drawings]

FIG. 1 is a front view of a tester of the present invention.

FIG. 2 is a schematic block diagram of a tester.

FIG. 3 is a circuit diagram of a range selection switch.

[Explanation of symbols]

1 → Tester 5 → Front panel 6, 7 → Display 10 →
Range selection switch 11 → polarity change switch 13 → voltage setting switch 3
0 → DC power supply circuit 31 → current source circuit 32 → current range selection circuit 33 →
Measurement circuit 34 → Test resistance 35 → Voltage measurement circuit 36 → Current detection circuit 37 → Current sensor 38 → Resistance range selection circuit 39 →
Arithmetic circuit 50 → Power supply circuit 51 → Oscillator 52 → Voltage / power amplifier

Claims (2)

[Claims] 1. A current source circuit connected to a DC power source circuit via a polarity change switch, a measurement circuit connected to the current source circuit, and a voltage across a test resistor provided in the measurement circuit. A voltage measurement circuit, a current detection circuit that detects a current flowing through the measurement circuit with a current sensor, and a resistance value of the sample resistor is calculated based on a measurement value of the voltage measurement circuit and a detection value of the current detection circuit. An arithmetic circuit, a digital display for respectively displaying the detected current value and the calculated resistance value, and a predetermined combination of a current range given to the current source circuit and a resistance range given to the current detection circuit with one touch. An electrical performance tester comprising a selectable range selection switch. 2. The electrical performance tester according to claim 1, further comprising a power supply circuit including a voltage setting switch, an AC / DC switching switch, an oscillator, and a voltage / power amplifier.