JPH07306238A - Noise tester - Google Patents

Abstract

PURPOSE:To realize a reliable noise test by controlling the switching period of a charge/discharge switch to the discharge side in synchronism with the phase difference of AC polyphase voltage of an imaginary noise source. CONSTITUTION:A DC voltage from a power supply unit 11 is boosted through a DC-DC converter 21 to a high voltage. Three-phase AC voltage from a noise source 9 is converted through a half-wave rectifying/comparing circuit 26 into a pulse signal which is fed, as a switch driving signal synchronized with the phase difference of three-phase AC voltage, to a semiconductor switch 23. The switch 23 connects a noise generating circuit 22 to the charging side when the switch driving signal is '0' and connects the circuit 22 to the discharge side. A charge/discharge capacitor charged with a high voltage during the period in which it has been connected to the charging side is discharged immediately upon switching to the discharging side so long as a part to be tested is connected, generating a pulsation test noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, a power supply line, etc. which are directly connected when an electronic device is used.
A noise test that tests the resistance (hereinafter referred to as noise resistance) to noise that enters from a power supply line, etc., or a power supply device / power supply line, etc. that has almost the same standard as these, referred to below as the "supposed noise source." Regarding vessels.

Recent electronic devices are becoming smaller and lower in power consumption, and therefore are delicate, and even if they are damaged by noise, there are many cases of deterioration of operating characteristics due to noise. The importance is increasing more rapidly than ever before.

[0003]

2. Description of the Related Art Of course, noise testers for testing the noise resistance of electronic equipment have been commercially available.

FIG. 7 shows a configuration example of a conventional commercial noise tester. In the figure, 10 is an AC power supply, and a block drawn with a chain double-dashed line is a noise tester. In the noise tester, 11 is a power supply unit, 1 is a DC high voltage generator, 2 is a noise generation circuit, and 3 is a noise tester. The charge / discharge switch 4 is a switching cycle control circuit, and 5 is a connecting device.

The outline of the operation of the noise tester of FIG. 7 will be described below. The power supply unit 11 generates a synchronization signal for the switching cycle control circuit 4 using alternating current supplied from an alternating current power supply 10 such as a 100 V commercial power supply, rectifies the alternating current and applies it to the direct current high voltage generator 1. . The DC high voltage generator 1 is composed of a DC-DC converter, and its output voltage is connected to the charging side terminal of the charge / discharge switch 3. The discharge side terminal of the charge / discharge switch 3 is connected to the device under test through a connecting device 5 such as a socket.

The noise generating circuit 2 for generating a high voltage noise waveform is a series circuit of a charging / discharging capacitor C and a resistor R, which are main components as shown in the figure, and is charged by the charging / discharging switch 3. Side, that is, the terminal on the side of the high-voltage DC generator 1, or the discharge side, that is, the terminal on the side of the device under test.

A high voltage current is discharged in an impulse at once from the capacitor C charged to a high voltage by the DC high voltage generator 1 during the period switched to the charging side, during the period switched to the discharging side. As a result, test noise is added to the device under test. The waveform of this test noise is a quasi-square wave with a pulse width of about 5 μs and an amplitude maximum of about 2 kV.

The switching cycle of the charging / discharging switch 3 to the charging side and the discharging side is controlled by the switching cycle control circuit 4,
It is controlled by a synchronization signal generated by a method such as amplitude discrimination of 50 Hz or 60 Hz alternating current supplied from the alternating current power supply 10.

[0009]

However, conventionally, even if a good result was obtained as a result of a test with a commercially available noise tester, there was a problem that the deterioration of the characteristics was not actually reduced.

As a result of investigating the reason, in the conventional noise tester on the market, various conditions of the output noise are different from the conditions of the noise actually generated, that is, the conditions of the assumed noise source, and the pulse width and the amplitude are wider. It was found that the largest reason is that it is distributed in the.

In order to meet the above conditions, noise waveforms such as the rise time of the quasi-rectangular waveform, the pulse width, the pulse amplitude, and the way of drawing the skirt are faithfully simulated. It is also desirable to consider the application synchronized with.

On the other hand, it is necessary to test a plurality of parts in the device under test. However, in the conventional noise tester, the test of a plurality of parts under test has to be done by manual switching. There was a difficulty that required.

Further, since the noise tester handles a high voltage, it is necessary to give sufficient consideration to electric shock accidents to the human body, but conventional commercial products have not been given sufficient consideration. Therefore, the object of the present invention is, except for the above-mentioned drawbacks of the prior art, that a test noise synchronized with a polyphase AC of an assumed noise source can be generated first, so that a reliable noise test can be performed, and then a plurality of tested parts can be tested. It is an object of the present invention to provide a noise tester capable of automatically and rapidly performing the above test, and further provided with a warning against an electric shock accident to a human body.

[0014]

FIG. 1 is a block diagram showing the principle of the present invention. According to the invention described in claim 1, a DC high voltage generator 1, a noise generation circuit 2 for generating a high voltage noise waveform mainly using a charging / discharging capacitor, and a noise generation circuit 2 for charging side, that is, DC high voltage generation. A charge / discharge switch 3 that is switch-connected to a terminal on the device 1 side or a discharge side, that is, a terminal on the device under test, a switching cycle control circuit 4 that controls the switching cycle of the charge / discharge switch 3, and a charge / discharge switch. In the noise tester provided with the connection tool 5 for adding the noise given from the noise generation circuit 2 to the device under test via the switch 3, the assumed noise source 9 is input instead of the switching cycle control circuit 4. A feature is that an interphase phase difference drive circuit 6 for controlling a switching cycle of the charge / discharge switching device 3 to the discharge side is connected so as to be synchronized with the interphase phase difference of the multiphase alternating current.

According to a second aspect of the present invention, an equivalent rotary switch 7 for sequentially applying noise to each of a plurality of parts under test in the device under test, and a rotary switch drive circuit 8 for driving the equivalent rotary switch 7, A plurality of connecting devices 5-1, 5-2, ..., 5-n connected to the part to be tested are provided, and the charge / discharge switch 3 is provided on the rotary shaft side terminal of the equivalent rotary switch 7.
Of the equivalent rotary switch 8 is connected to a corresponding connecting device corresponding to each of the plurality of switching side terminals of the equivalent rotary switch 8.

According to a third aspect of the invention, the rotary switch drive circuit 8 counts the number of times of switching to the discharge side, and every time the number of phases of the multi-phase alternating current or the number equal to an integral multiple thereof is reached, the switching side is switched to one. The counter is characterized in that it is a counter that sends out a rotary drive signal that advances the equivalent rotary switch 7 step by step.

According to a fourth aspect of the present invention, a winding-shaped ring-shaped magnetic core is provided, and a Zener diode and a light emitting diode connected in parallel are connected in series with a protective resistor between both ends of the winding. The inside of the ring of the ring-shaped magnetic core is connected to the alarm circuit, and an electric wire connecting the output of the DC high voltage generator 1 and the charging side terminal of the charge / discharge switch 3 or the discharge side of the charge / discharge switch. An electric wire connecting the terminal and the input of the connecting device 5 is arranged so as to penetrate therethrough.

According to a fifth aspect of the present invention, a winding-shaped ring-shaped magnetic core is provided, and a Zener diode and a light emitting diode connected in parallel are connected in series with a protective resistor between both ends of the winding. The alarm circuit is connected, and the inside of the ring of the ring-shaped magnetic core is arranged so that an electric wire connecting the rotary shaft side terminal of the equivalent rotary switch 7 and the discharge side terminal of the charge / discharge switch 3 passes through the ring. It is characterized by

According to a sixth aspect of the present invention, a plurality of ring-shaped magnetic cores having individual windings are provided, and a zener diode and a light emitting diode connected in parallel are provided with a protective resistor between both ends of the winding. The alarm circuits, which are connected in series with each other, are individually connected, and an electric wire that connects the plurality of switching side terminals of the equivalent rotary switch 7 and the corresponding connection device penetrates inside the ring of each ring-shaped magnetic core. It is characterized in that it is arranged as follows.

According to a seventh aspect of the present invention, the DC high voltage generator 1 is connected in parallel with an alarm circuit in which a Zener diode and a light emitting diode connected in parallel are connected to a protective resistor in series. And

[0021]

In the noise tester according to the first aspect of the present invention, the interphase phase difference drive circuit 6 receives the assumed noise source 9 as an input, detects the phase difference between the multiphase alternating currents, and charges / discharges the switch 3 Since the switching cycle to the discharge side of is controlled so as to be synchronized with the phase difference between the phases, not only the factors that determine the pulse waveform of the test noise, but also the application timing can be matched with the assumed noise source. A certain noise test can be done.

In the noise tester according to the second aspect of the present invention, the output noise of the noise generating circuit 2 is output to a plurality of devices in the device under test by the action of the equivalent rotary switch 7 which is rotationally driven by the rotary switch driving circuit 8. Since it is possible to sequentially add to each of the tested parts, a plurality of tested parts can be automatically and rapidly tested.

In the noise tester according to the third aspect of the present invention, the rotary switch drive circuit 8 is a counter, and the number of times of switching to the discharge side is counted to be equal to the number of phases of polyphase alternating current or an integral multiple thereof. Whenever the number reaches the number, the rotation drive signal for stepping up the equivalent rotary switch 7 is sent by one switching side terminal, so that the test noise is applied every time the number of phases equal to the number of phases of the assumed noise source, or an integral multiple of times. , Application can be sequentially shifted in sequence.

In the noise tester according to the invention described in claims 4 to 6, a ring-shaped magnetic core having a winding is provided, and a zener diode and a zener diode connected in parallel are provided between both ends of the winding. An alarm circuit in which a protective resistor is connected in series to the light emitting diode is connected, and the inside of the ring of the ring-shaped magnetic core is connected to the output of the DC high voltage generator 1 and the charging side terminal of the charge / discharge switch 3 in claim 4. The electric wire for connecting with the electric wire for connecting with or the electric wire for connecting the discharge side terminal of the charge / discharge switch 3 and the input of the connecting device 5 is arranged so as to penetrate therethrough. Charge / discharge switch 3
The electric wire for connecting to the discharge side terminal of the above is arranged so as to penetrate therethrough, and in the claim 6, the electric wire for connecting between each of the plurality of switching side terminals of the equivalent rotary switch 7 and the corresponding connection device penetrates therethrough. Arrange.

Therefore, in any case, when the test noise is applied to the portion to be tested, an induced electromotive force is generated in the winding applied to the ring-shaped magnetic core, and the light emitting diode connected to this winding is generated. When is lit or blinks, it gives an alarm against electric shock to the human body. The overvoltage of the light emitting diode is protected by the Zener diode. Moreover, the closer the location of the ring-shaped magnetic core is to the site under test, the better the state of application to the site under test can be grasped, and the reliability of the alarm will increase.

Finally, in the noise tester according to the seventh aspect of the present invention, an alarm circuit in which a Zener diode and a light emitting diode connected in parallel and a protection resistor are connected in series is connected in parallel to the DC high voltage generator 1. Since it is connected, even if the test noise is not applied to the part under test, it lights up as long as the DC high voltage generator 1 is operating, and gives a comprehensive alarm. The overall overvoltage is protected by a protective resistor,
The overvoltage of the light emitting diode is protected by the Zener diode.

[0027]

FIG. 2 shows an embodiment of an interphase phase difference drive circuit which is the most characteristic block of the present invention. In this embodiment, a three-phase alternating current is obtained as an input from an assumed noise source.

In FIG. 2, a, b and c are three-phase AC input terminals.
Child, 12 is a three-phase transformer, D₁, D₂And D ₃Is a rectifier
Mode, OP is operational amplification used as a comparator
V_RIs applied to the- (minus) terminal of OP
It is a reference voltage.

FIG. 3 shows at each point in the circuit of FIG.
It is a time chart which shows a signal waveform. This embodiment will be described below with reference to FIGS. 2 and 3. The three-phase alternating current applied from the input terminals a, b and c is Δ-Y converted by the three-phase transformer 12, and then half-wave rectified by the rectifying diodes D ₁ , D ₂ and D ₃ , and the point p is It is applied to the + (plus) terminal of the operational amplifier OP via. Since the operational amplifier OP is used as a comparator, and the reference voltage V _R is applied to its − terminal, the comparator outputs a static voltage every time the half-wave rectified voltage applied to the + terminal exceeds the reference voltage V _R. Output.

Therefore, from the point q, as shown by hatching in FIG. 3, a pulse train of a positive voltage synchronized with the phase difference between phases of the output of the assumed noise source 9 is transmitted. FIG. 4 shows an embodiment of the ring-shaped magnetic core provided with the winding of the present invention. In the figure, 13 is a ring-shaped magnetic core, and in this embodiment, a ferrite ring core which is a ferromagnetic material is used. Further, 14 is a winding wound around the ring core, a and b are both terminals thereof, and 15 is an electric wire penetrating through the ring of the ring core.

When a high-frequency alternating current or a rapidly changing impact current flows through the wire 15, an induced electromotive force is generated in the winding 15 and a voltage is generated between both terminals d and e. Meanwhile, FIG.
Is an embodiment of the alarm circuit of the present invention. LED in the figure
Is a light emitting diode, ZD is a zener diode, R _p is a protective resistor, and f and g are both terminals of the alarm circuit.

When a direct current voltage having a polarity as shown in the figure and having an appropriate magnitude is applied between the terminals f and g, the light emitting diode LED emits light to give an alarm. Zener diode ZD
Is for the purpose of protecting the light emitting diode LED from overvoltage,
Further, the protection resistor R _P is used for the purpose of protecting both the above-mentioned components from overvoltage and overcurrent.

FIG. 6 shows an embodiment of the overall structure of the present invention. This embodiment includes claim 3, claim 6, and claim 7.
It is about. In the figure, 21 is a DC-DC converter that receives a DC voltage from the power supply unit 11, 22 is a noise generation circuit, 23 is a semiconductor switch, and 26 is a supposed noise source 9 to 3.
Half-wave rectification comparison circuit that receives phase alternating current, 27 is a semiconductor switch group, 28 is a counter, 13-1 to 13-n are ferrite ring cores, LED1 to LEDn are light emitting diodes, ZD1 to ZDn are zener diodes, and 25- 1 to 25-n are a coaxial cord and a crocodile clip, respectively.

The correspondence relationship with the blocks in FIG. 1 showing the principle blocks of the present invention is as follows. That is, the DC-DC converter 21 in FIG. 6 corresponds to the DC high voltage generator 1 in FIG. 1, the noise generation circuit 22 corresponds to the noise generation circuit 2, the semiconductor switch 23, the half-wave rectification comparison circuit 26. ,
The semiconductor switch group 27 and the counter 28 correspond to the charge / discharge switch 3, the equivalent rotary switch 7, and the rotary switch drive circuit 8, respectively. The coaxial cable and crocodile clips 25-1 to 25-n correspond to the connecting devices 5-1 to 5-n.

The operation of this embodiment will be described below. The DC voltage supplied from the power supply unit 11 is DC-
The DC converter 21 boosts the voltage to a high voltage of approximately 2 kV.

On the other hand, the three-phase alternating current supplied from the assumed noise source 9 is half-wave rectified in the half-wave rectification comparison circuit 26 and converted into a reference voltage as described with reference to FIG. 2 showing an embodiment of the interphase phase difference drive circuit. It is compared and discriminated and converted into a pulse signal, which is sent to the semiconductor switch 23 as a switch drive signal in synchronism with the phase difference between the three-phase alternating current, and at the same time applied to the counter 28 as a counted pulse signal.

The semiconductor switch 23 is a switch made of known semiconductor parts, and is a noise generation circuit when the switch drive signal sent from the half-wave rectification comparison circuit 26 is "0".
22 is connected to the charging side, that is, the output side of the DC-DC converter 21, and in the case of "1", the noise generating circuit 22 is connected to the discharging side,
That is, it is switched so as to be connected to the input side of the semiconductor switch group 27. The noise generation circuit 22 is a simple circuit in which a charging / discharging capacitor and a resistor are connected in series. The semiconductor switch group 27 is a group of a plurality of switches made of the above-mentioned known semiconductor components, and is a drive shaft side terminal, that is, a switched side terminal directly connected so as to equivalently form a rotary switch. .

The charging / discharging capacitor charged to a high voltage during the period switched to the charging side is discharged at once if the portion to be tested is connected when switched to the discharging side, and a pulsed test is conducted. Generate noise. The half-value width (pulse width) of this pulse-shaped test noise is variable within the range of 0.1 to 10 μs.

Each of the plurality of switching side terminals of the semiconductor switch group 27 has a coaxial cord and crocodile clips 25-1 to 25-n.
Is connected to the corresponding tested part in the device under test via any one of the above.

The counter 28 is a so-called 3-to-1 counter which counts the number of input pulses, and outputs an output pulse every time three pulses are counted, and the output pulse is a semiconductor signal as a switch rotation drive signal. It is applied to the switch group 27. Therefore, the timing of the switch rotation drive signal is a timing at which the test noises of three phases are sequentially and stepwise switched so that the test noises of three phases are applied to the next test portion after the test noises of one phase are completely applied. And is time efficient. Of course, in this case, 3 to 1
Instead of a counter (3 × i) to 1 counter (where i
Is an arbitrary integer), and after three-phase noise has been applied to one test site a plurality of times n times, it is possible to switch to the next test site.

When the noise tester is turned on and the DC-DC converter 21 starts to generate a high voltage, the zener diode is connected even if the part under test is not connected at all.
The light emitting diode LED0 protected by ZD0 emits light to give an alarm for electric shock.

Next, when the test noise is sent through any of the test noise sending routes, only the light emitting diode of the alarm circuit belonging to the route emits light to give an alarm.
The fact that the test noise is being sent and the route that is being sent can be known at the same time.

[0043]

As described above, according to the present invention, the test noise synchronized with the polyphase AC of the assumed noise source can be obtained.
A reliable noise test can be performed, a plurality of parts to be tested can be automatically and rapidly tested, and a noise tester equipped with a warning against an electric shock accident to a human body can be realized.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is an example of an interphase phase difference drive circuit.

FIG. 3 is a time chart showing waveforms at respective points in the circuit of FIG.

FIG. 4 is an example of a ring-shaped magnetic core provided with windings.

FIG. 5 is an example of an alarm circuit.

FIG. 6 is an example of the overall configuration of the present invention.

FIG. 7 is a configuration diagram of a conventional commercially available noise tester.

[Explanation of symbols]

 1 DC high voltage generator 2 Noise generation circuit 3 Charge / discharge switcher 4 Switching cycle control circuit 5 Connection device 6 Phase-to-phase phase difference drive circuit 7 Equivalent rotary switch 8 Rotary switch drive circuit 9 Assumed noise source

Claims (7)

[Claims] 1. A DC high voltage generator (1), a noise generating circuit (2) for generating a high voltage noise waveform mainly by a charging / discharging capacitor, and a noise generating circuit (2) on the charging side, that is, At the terminal on the DC high voltage generator (1) side,
Alternatively, a charge / discharge switch (3) that is switched and connected to a terminal on the discharge side, that is, a device under test, a switching cycle control circuit (4) that controls the switching cycle of the charge / discharge switch (3), and the charge / discharge switch. A noise tester including a connecting device (5) for adding noise given from the noise generating circuit (2) to the device under test via a device (3), in place of the switching cycle control circuit (4). , An interphase phase difference drive circuit for controlling the switching cycle of the charge / discharge switch (3) to the discharge side so as to synchronize with the interphase phase difference of the multi-phase alternating current of the postulated noise source (9). 6) A noise tester characterized by being connected. 2. An equivalent rotary switch (7) for sequentially applying noise to each of a plurality of parts under test in the device under test, and a rotary switch drive circuit (8) for driving the equivalent rotary switch (7), A plurality of connecting devices (5-1, 5-2, connected to the site to be tested)
..., 5-n), the discharge side terminal of the charge / discharge switch (3) is connected to the rotary shaft side terminal of the equivalent rotary switch (7), and the plurality of equivalent rotary switches (8) are connected. The noise tester according to claim 1, wherein the connecting device corresponding to each of the switching side terminals is connected. 3. A rotary switch drive circuit (8) counts the number of times of switching to the discharge side, and every time the number of phases of the polyphase alternating current or the number equal to an integral multiple thereof is reached, one rotary switch side terminal is provided with an equivalent rotary switch. 3. A counter for transmitting a rotation drive signal for stepping (7).
The noise tester described in. 4. A ring-shaped magnetic core provided with a winding, and between both ends of the winding, an alarm circuit in which a Zener diode and a light emitting diode connected in parallel and a protective resistor are connected in series is connected, Inside the ring of the ring-shaped magnetic core, an electric wire connecting the output of the DC high voltage generator (1) and the charge side terminal of the charge / discharge switch (3), or the discharge side terminal of the charge / discharge switch The noise tester according to claim 1, wherein an electric wire connecting the input terminal of the connection device (5) and the input terminal of the connection device (5) is provided so as to penetrate therethrough. 5. A ring-shaped magnetic core provided with a winding, and an alarm circuit in which a Zener diode and a light emitting diode connected in parallel and a protection resistor are connected in series is connected between both ends of the winding. The inside of the ring of the ring-shaped magnetic core is connected to the rotary shaft side terminal of the equivalent rotary switch (7) and the charge / discharge switch (3).
The noise tester according to claim 2 or 3, wherein an electric wire for connecting to the discharge side terminal is provided so as to penetrate therethrough. 6. An alarm comprising a plurality of ring-shaped magnetic cores having individual windings, and a Zener diode and a light emitting diode connected in parallel with a protective resistor connected in series between both ends of the winding. The circuits are individually connected, and the insides of the rings of each of the ring-shaped magnetic cores are arranged so that the electric wires for connecting the plurality of switching side terminals of the equivalent rotary switch (7) and the corresponding connecting devices individually pass therethrough. The noise tester according to claim 2 or 3, wherein the noise tester is provided. 7. The high-voltage DC generator (1) is connected in parallel with an alarm circuit in which a Zener diode and a light emitting diode connected in parallel are connected in series with a protective resistor. 7. The noise tester according to claim 6.