JPS6166170A - Continuity checker - Google Patents

Abstract

PURPOSE:To enable judgement on a connecting condition of a specimen circuit, by overlapping an AC current on a DC current of the power source in the specimen circuit, the AC current being available for change in tune with inductance or capacitance. CONSTITUTION:The power source unit 3 is connected with specimen circuit UUT1 and reference resistance 4 in series and on both ends of the resistance 4, both DC and AC voltages inversely proportional to DC resistance and impedance of the UUT1 drops and the dropped voltage is applied to a filter circuit unit 5 from a joint of the resistance 4. The circuit unit 5 divides the dropped voltage into DC and AC voltages and the AC voltage is converted to a DC voltage and it is transmitted to a comparing circuit unit 7 as output signals 5a, 5b. On the other hand, a DC output voltage of the reference voltage setting unit 6 is transmitted to the unit 7 as signals 6a, 6b and the signal 5a is compared with the 5b and the signal 5b with the 6b respectively and when signals 5a, 5b are higher than 6a, 6b, then signals 7a, 7b turn on DC and AC indicating diodes at an indicator 2 and reversely, when the signals 5a, 5b are lower, than they turn off them for warning of non-continuity.

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,
The present invention relates to a continuity checker that determines whether there is continuity or not.

[Prior art]

First, a conventional continuity checker will be explained using FIG. 1. Figure 1 shows a configuration diagram of a conventional continuity checker. In Figure 9, fl) is the circuit under test (UNIT U
NDERTB8T and below is abbreviated as UU'l'), 12) is U
IJT (A notification unit that sounds a buzzer when the DC resistance of 11 is low.

(31 is composed of a UUT (11) and a power supply section that supplies direct current to the notification section.

Next, the operation of the conventional continuity checker shown in FIG. 1 will be explained. Power supply section (31 is a DC cylinder, source.

DC current is supplied to OUT (11) and the notification unit (2) connected in series, and when the DC resistance of UUT (11) is low, the voltage dropped to UUT (11) is low, so the notification unit (2)
The voltage of the power supply section is directly applied to both ends of 1, and the buzzer sounds. Conversely, when the DC resistance of UUT (1) is high, the UUT
Since the voltage dropping to 11) also increases, the alarm part (2)
The voltage applied across both ends is low and the Lipzer does not sound.

From the above results, it is determined that when the buzzer sounds, it is a conductive state, and when it does not sound, it is determined that it is a non-conductive state.

However, in conventional continuity checkers that are configured and operate in this way, if 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 UUT (11) is conductive. [Summary of the Invention] This invention was made to improve these drawbacks. A filter circuit section, a reference voltage setting section, a comparison circuit section, and a reference resistor are provided, and a resistance component, an inductance component, or a capacitance component is provided.

The present invention provides a continuity checker configured to be able to determine the continuity state of the UUT (11).

[Embodiments of the invention]

FIG. 2 is a diagram showing an embodiment of the continuity checker according to the present invention. In FIG. 9, (11 to 31 are the same as in FIG. , (5a) is the filter circuit section DC output signal.

(5b) is the output signal for AC of the filter circuit section, (6) is the reference voltage setting section, (6a) is the output signal of the reference voltage setting section for DC, (6b) is the output signal for AC of the reference voltage setting section, (7) (7a) is the comparison circuit section, and (7a) is the comparison circuit section DC output signal.

(7b) is an output signal for AC of the comparison circuit section.

In such a configuration, the UUT (11) 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 UUT El+ and an AC voltage that is inversely proportional to the impedance of UUT (11) are dropped across the UUT (El+), and these dropped voltages are 141 connection point to filter circuit section +5
The filter circuit unit (51) separates the voltage drop into a DC voltage and an AC voltage, and the AC voltage is converted into a DC voltage, and the filter circuit unit DC output signal (5a) and the filter circuit are sent to the filter circuit unit (51). The reference voltage setting section (6), which becomes an output signal (5b) for AC and is sent to the comparison circuit section (7), is a variable resistor with a scale that can continuously vary the DC voltage. and a variable resistor with a scale that sets the DC voltage according to the DC resistance of the DC output voltage.The DC output voltage of each is determined by the reference voltage setting part DC output signal (6a), the output rate voltage setting part DC output signal (6b) The comparison circuit section (
7).

The comparison circuit section (7) outputs the filter circuit section DC output signal (5a) and the reference voltage setting section DC output signal (6a), and also outputs the filter circuit section AC output signal (5b) and the reference voltage setting section AC output signal. and the output signal (6b) for
When the filter circuit section DC output signal (5a) is higher than the reference voltage setting section DC output signal (6a), the comparator circuit section DC output signal (7a) becomes (ni), and conversely when it is lower, it becomes (ni). LOW). Similarly, the filter circuit section AC output signal (5b) is the reference voltage setting section AC output signal (6b).
), the comparator circuit AC output signal (7b) is (
It becomes (Hi), and conversely, when it is high, it becomes (LOW). 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 1 m1J, the light emitting diode for DC notification lights up, and conversely, ri, When owJ, the light goes out.Similarly, when the comparator circuit AC output signal (7b) is 1m1J,
The light emitting diode for AC notification lights up, and on the other hand, [Lo
The lights go out when wJ.

When the light emitting diode is on, it means a conductive state, and when it is off, it means a non-conductive 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, (81 is a terminal board, (91 is a transformer,
υ is the connecting 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 (81) are shown.
TB-2) and the terminal (T-2) of the transformer (9), and the terminal (TB-a) of the terminal board (8) and the terminal (T-3) of the transformer (9) are connected with connection cable 00. It must be connected ('-0) Here, the terminal (T) of the terminal board (8) as shown by the dotted line in
B-1) and transformer (9) terminal (T-2), terminal board (81 terminal (TB-2) and transformer (91 terminal (T-2))
Check continuity between T-1.

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 (91), it is equal to 0Ω in terms of 1M current, but In terms of alternating current, it has impedance.The same is true between the terminal board (81 terminal (TB-2)) and the transformer (91 terminal (T-1)), and the relationship between these terminals is shown in Figure 2. By using the terminal board (terminal 81 (TB
-1) and the terminal (T-1) of the transformer (9), the terminal board (
8) terminal (TB-2) and transformer (9) terminal (T-
2) between the terminal (TB-3) of the terminal board (8) and the transformer (
As for the DC resistance and impedance between terminals (T-3) in 9), both are equal to 0Ω, there is continuity in both DC and AC, and the wiring between these terminals is correct. can be determined. 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 OI, if the frequency of the alternating current of the power supply section (31) is increased, the impedance between the terminals of the transformer (9) becomes thicker, and the difference in DC resistance with the connection cable 11 becomes thicker, making it possible to distinguish between conduction and non-continuity.On the other hand, when the connection cable haze is routed for a long time and has inductance, When the frequency of the alternating current of the power supply section (3) is lowered, the impedance of the connection cable aG becomes smaller, and it is possible to distinguish between conduction and non-conduction.

Furthermore, if the comparison voltage of the reference voltage setting section is set according to the impedance of the transformer (9), even more severe determination of conduction or non-conduction of the circuit network can be made.

〔Effect of the invention〕

As described above, according to the present invention, UUT (1
The present invention has the advantage that a continuity test can be performed even when the impedance of 1 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 continuity checker, FIG. 2 is a diagram showing an example of the conduction checker according to the present invention, and FIG. 3 is a diagram showing an example of use of the continuity checker according to the present invention. The middle (1) is the circuit under test. +21 is the notification part, (31 is the power supply part, (4) is the reference resistor, (5) is the filter circuit part, (5a) is the filter circuit part DC output signal, (5b) is the filter circuit part AC output signal (6) is the reference voltage setting section, (6a) is the reference voltage setting section DC output signal, (6b) is the reference voltage setting section AC output signal, C7) is the comparison circuit section, (7a) is the comparison circuit section (7b) is a comparison circuit section AC output signal, (8) is (9) one terminal board, (9) is a transformer, and 1It1 is a connection cable. It should be noted that the same or equivalent parts in FIG. 0 are denoted by the same reference numerals.

Claims (1)

[Claims] A continuity checker that detects the current flowing from a power supply to a circuit under test and determines the presence or absence of continuity uses an alternating current whose frequency can be varied depending on the DC current and the inductance or capacitance of the circuit under test to be applied to the circuit under test. A power supply unit to be supplied, a reference resistor that is connected in series to the circuit under test and drops the voltage in proportion to the current flowing through the circuit under test, and an output between the reference resistor and the circuit under test, a filter circuit section that separates it into a DC component and an AC component; a reference voltage setting section that sets a criterion for determining whether the circuit under test is conductive or non-conductive with respect to the power supply; and an output of the filter circuit section and the reference voltage setting section. It consists of a comparison circuit section that compares the output from the
Alternatively, the continuity state of the circuit under test can be determined by passing an alternating current whose frequency can be varied according to the inductance or capacitance of the circuit under test superimposed on the DC current from the power supply to the circuit under test having a capacitance component. A continuity checker that is characterized by: