JPS6069569A - Conduction checker - Google Patents

Abstract

PURPOSE:To discriminate the conductive state of a circuit (UUT) to be measured which has a resistance component, inductance component or capacitance component by superposing an AC current upon the DC current at a power supply source, and providing a filter circuit part, reference voltage part, comparing circuit part, and reference resistor. CONSTITUTION:The UUT1, reference resistor 4, and power supply source part 3 are connected in series, a DC voltage inversely proportional to the DC resistance of the UUT1 and an AC voltage inversely proportional to the impedance of the UUT1 drops across the UUT1, and those dropping voltages are applied from the connection point of the UUT1 and reference resistor 4 to the filter circuit part 5. The filter circuit part 5 separates the dropping voltage into a DC voltage and an AC voltage. The reference voltage part 6 is a DC constant voltage power supply source servicing a reference to decide whether the UUT1 is conductive in terms of DC or AC. The comparing circuit part 7 compares the DC output signal 5a for the filter circuit part with the DC output signal 6a for the reference voltage part, and the AC output signal 5b for the filter circuit part with the AC output signal 6b for the reference voltage part.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention detects a current flowing from a power supply to a circuit under test,
This invention relates to a continuity checker that determines the presence or absence of continuity.

[Prior Art] First, a conventional continuity checker will be explained using FIG. 1. FIG. 1 shows a configuration diagram of a conventional continuity checker. In FIG. 9, (1) indicates the circuit under test (hereinafter abbreviated as UUT) UNIT, UNDER, TKS'l'.

(2) is a notification section that sounds a buzzer when the DC resistance of UUT (1) is low, and (3) is composed of a power supply section that supplies DC current to UUT (11) and the notification section.

Next, the operation of the conventional continuity checker shown in FIG. 1 will be explained. 'The power supply section (3) is a DC power supply.

When a DC current is supplied to the UUT (11) and the notification unit (2) connected in series, and the DC resistance of the UUT (1) is low,
Since the voltage that drops to UUT (11) is also low, the voltage of the power supply is directly applied to both ends of the notification unit (2) and the buzzer sounds. Conversely, when the DC resistance of UUT (ll) is high,
The voltage that drops to the UT (1) also becomes high, so the voltage applied to both ends of the notification section (2) becomes low and the buzzer does not sound.

From the above results, it is determined that when the buzzer sounds, it is a conductive state, and when the buzzer sounds, it is determined that it is a non-conductive state.

However, in conventional continuity checkers that are configured and operate in this manner, if the UUT (11) has an inductance component such as a transformer or coil, it is determined to be conductive, and if it has a capacitance component such as a capacitor, it is determined that it is conducting. T (11) had the drawback of being judged as non-conducting.

[Summary of the Invention] This invention was made to improve these drawbacks, and the power source uses an alternating current whose frequency can be changed according to the inductance or capacitance of tJUT (11) in addition to the direct current. Superimposed with the filter circuit section.

A reference voltage section, comparison circuit section, and reference resistor are provided.

It has a resistance component, an inductance component, or a capacitance component. The present invention provides a continuity checker configured to be able to determine the continuity state of a UUTfl.

[Embodiment of the Invention] FIG. 2 is a diagram showing an embodiment of the continuity checker according to the present invention, and in FIG. 1, (1) to (3) are the same as in FIG. 1. (4) is the reference resistor, (5) is the filter circuit section, and (5a) is the filter circuit section DC output signal.

(5b) is the filter circuit section AC output signal, (6) is the reference voltage section? (6a) is the reference voltage section DC output signal;
(<51)) is the output signal for the crystal pressure section AC, and (7) is the comparison circuit section.

(7a) is the output signal for DC of the comparison circuit section, and (7b) is the output signal for AC of the comparison circuit section.

In such a configuration, tJUTt1+ and the reference resistor (
4) and the power supply section (3) are connected in series, and the reference resistor (4) is connected in series.
), a DC voltage that is inversely proportional to the DC resistance of the UUT (1) and an AC voltage that is inversely proportional to the impedance of the UUT (11) drop, and these dropped voltages are .

It is sent to the filter circuit section (5) from the connection point between U U T (11) and the reference resistor (4).

The filter circuit section (5) separates the dropped voltage into a DC voltage and an AC voltage, and the AC voltage is converted into a DC voltage, and a filter circuit section output signal (5a) for DC and a filter circuit section output for AC, respectively. The signal becomes a signal (5b) and is sent to the comparison circuit section (7).

The reference voltage section (6) is a DC constant voltage power supply that serves as a reference for determining whether the UU'T (1) is conductive or non-conductive in DC or AC, and each reference voltage section outputs a DC output signal. (6a) and a reference voltage section AC output signal (6b), which are sent to the comparison circuit section (7).

The comparison circuit section (7) receives the filter circuit section DC output signal (5a) and the reference voltage section DC output signal (6a).

Also, the filter circuit section AC output signal (5b) and the reference voltage section AC output signal (6b) are compared respectively.

When the output signal for DC of the filter circuit section (5a) is higher than the output signal for AC of the reference voltage section (5b), the output signal for DC of the comparator circuit section (7a) becomes "I1", and when it is low for correspondence, it becomes "1-". Similarly, when the filter circuit section AC output signal (5b) is higher than the reference voltage section AC output signal (6b), the comparison circuit section AC output signal (7b) becomes "H". , when it is low in correspondence, it becomes l-bowl. The comparison circuit section DC output signal (7a) and the comparison circuit section AC output signal (7b) are each sent to the notification section (2).

The notification section (2) consists of a light emitting diode for DC notification and a light emitting diode for AC notification, and when the comparison circuit section DC output signal (7a) is "H", the light emitting diode for DC notification lights up, and the light emitting diode for DC notification lights up, The light goes out when it is “LOW”. Similarly, when the comparison circuit AC output signal (7b) is "H",
The light emitting diode for AC notification lights up, and on the other hand it goes l-low.
The lights are turned off when .

When the light emitting diode is on, it means a conducting state, and when it is off, it means a non-conducting state.

An example of the use of this invention shown in FIG. 3 will be described below.

FIG. 3 is a diagram showing an example of the use of the continuity checker according to the present invention, in which (8) is a terminal board, (9) is a transformer, (
1 This is the old home connection cable.

In Figure 3, the terminal (TB-1) of the terminal board (8), the terminal (T-1) of the transformer (9), and the terminal (TB-1) of the terminal board (8) are shown.
TB-1) and the terminal (T-2) of the transformer (9), the terminal ('rB-3) of the terminal board (8) and the transformer, x, +91
(7) The terminals (T-6) must be connected with connection cables Q.

Here, the terminal (T) of the terminal board (8) as shown by the dotted line in
B-1) and transformer (9) terminal (T2) + terminal board (
8) terminal (TB-2) and transformer (9) terminal (T-
1) Check continuity between the two.

Since the coil of the transformer (9) is interposed between the terminal (TB-1) of the terminal board (8) and the terminal (T-2) of the transformer (9), it is equal to 0Ω in terms of DC, but , AC has impedance. The same is true between the terminal (TB-2) of the terminal board (8) and the terminal (T-1) of the transformer (9), and the distance between these terminals is U U T (1 ), by using the conductor 1α checker according to the present invention, it is possible to determine that there is conduction in direct current but non-conduction in alternating current. and the terminal (T-1) of the transformer (9), between the terminal (TB-2) of the terminal board (8) and the terminal (T-2) of the transformer (9), and between the terminal (TB-3) of the terminal board 18). ) and the terminal (T-3) of the transformer (9), both the DC resistance and the impedance are equal to 0Ω, so a conductive state is exhibited both in terms of DC and AC.

It can be determined that the wiring between these terminals is correct.

At this time, if the inductance between the terminals of the transformer (9) is small and there is little difference from the DC resistance of the connecting cable (IQ), if the frequency of the alternating current of the power supply section (3) is increased, the inductance between the terminals of the transformer (9) The impedance of the connection cable becomes larger, and the difference in DC resistance of the connection cable becomes larger, and the continuity and
Non-conduction can be determined.

When the connecting cable (II) is routed for a long time and has inductance, lowering the frequency of the alternating current of the power supply section (3) will reduce the impedance of the connecting cable i11, making it possible to determine whether it is conductive or non-conductive. I can do things.

[Effects of the Invention] As described above, the present invention has the advantage that continuity testing can be performed even when the impedance of the UUT (11) is a resistance component, an inductance component, or a capacitance component.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional conduction checker, and Fig. 2 shows an embodiment of the continuity checker according to the present invention. ) is the power supply section, (4) is the reference resistor, and (5) is the fill circuit section. (5a) is the filter circuit section DC output signal, (sb)
(6) is the filter circuit section AC output signal, and (6) is the reference voltage section. (6a) is the reference voltage section DC output signal t (6b) is the reference voltage section DC output signal, (7) is the comparison circuit section, (7
a) is the comparator circuit DC output signal, and (7b) is the comparator circuit AC output signal No. 11. FIG. 3 shows an example of the use of the continuity checker of the present invention. In FIG. 9, (8) is a terminal board, (9) is a transformer, (
11 is a connection cable. In Figure 4D, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa

Claims (1)

[Scope of claims] A continuity checker that detects the current flowing from a power supply to a circuit under test and thereby determines the presence or absence of continuity, includes a DC current and an interval whose frequency can be varied according to the inductance or capacitance of the circuit under test. a power supply section that supplies current to the circuit under test; a reference resistor that is connected in series with the circuit under test and reduces the voltage in proportion to the current flowing through the circuit under test; and the reference resistor and the circuit under test. A filter circuit section that extracts the output between the
A reference voltage section that serves as a criterion for determining non-continuity. It is composed of a comparison circuit section that compares the output of the filter circuit section and the voltage from the reference voltage section, and a notification section that notifies the comparison result. , characterized in that the continuity state of the circuit under test is checked by superimposing an alternating current whose frequency can be varied according to the inductance or capacitance of the circuit under test on the DC current from the power supply. Continuity checker.