JPH08178989A - Load condition setter for power source characteristics inspection - Google Patents

Abstract

PURPOSE: To automatically deal with any output type power source by controlling the output of a sign voltage output unit based on the detection outputs of a power source voltage detector and a sign voltage detector and the input from an operating controller. CONSTITUTION: In a power source voltage detector 3, input terminals 11 and 12 to be connected to an object to be inspected are connected to one another, and a relay 35 is connected to an operation controller 6 by a voltage follower 37. A sign current detectors, 5, 4 connect signal voltage output units C, B to a terminal 12, and connects connecting points to the controller 6. The controller 6 connects the D-A converter 61 input (output) side to the follower 52 (operational amplifier 54) of the detector 5, and connects the D-A converter 62 input (output) side to the follower 42 (operational amplifier 38) of the detector 4, The follower 37 is connected to amplifiers 38, 54. The analog signal obtained by inputting the signal of an input unit and converting it by converters 61, 62 and the output voltage of the follower 37 are calculated by the amplifiers 38, 54, outputted to signal output ICs 71, 81, outputs C, B are controlled and detected by the detector 3 to obtain a voltage, which is made equal to the calculated voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load condition setting device for power supply characteristic inspection.

[0002]

2. Description of the Related Art Conventionally, a high-voltage power supply such as a copying machine has a constant current method and a constant voltage method as output methods. One of these methods outputs a positive voltage and the other outputs a negative voltage. There is one that outputs an AC voltage.

[0003]

As described above, since there are various types of high-voltage power supply systems, inspecting these high-voltage power supply devices requires an inspection device suitable for each system.

Further, the power supply unit needs to be inspected in a state where a load is applied to the power supply unit, and the load is different for each model in the copying apparatus and the like, so it is necessary to set an appropriate load, and many equipments are required. In addition, the cost burden for this was large, and it required labor such as changing the connection of the equipment.

[0005]

According to the present invention, a reference resistor, a power supply voltage detection unit, a negative voltage output unit in which a positive current detection unit is connected in series, and a negative voltage are provided between input terminals connected to a power supply device. Connect the current detection part in series with the positive voltage output part connected in series, and connect the operation / control part to each of the positive and negative voltage output parts to connect the power supply voltage detection part, the positive current detection part and the negative current detection part. Based on the detection output and the input from the operation / control unit,
It is intended to provide a load condition setting device for power supply characteristic inspection, which is configured to control the output of the positive / negative voltage output section.

It also has the following features.

The power supply voltage detector is composed of a plurality of relays connected to a connection point of a plurality of resistors connected in series between the input terminals.

Voltage followers are respectively provided between the output terminals of the power supply voltage detection unit, the positive current detection unit and the negative current detection unit and the operation / control unit.

The operation / control section is equipped with a D / A converter so that the positive / negative voltage output section can be controlled by a digital signal input from the outside.

Each of the positive and negative voltage output sections is composed of a positive and negative voltage output transformer and a rectifying diode.

[0011]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a load condition setting device L for power supply characteristic inspection according to the present invention. Mainly, a load condition setting unit 1, an overvoltage control unit 2 and a power supply voltage detection unit 3 are shown.
And a positive / negative current detection unit 5 and 4, and an operation / control unit 6.

The load condition setting unit 1 includes one input terminal 11 of the input terminals 11 and 12 for connecting to the power supply device A to be inspected.
Diodes D1 and D2 connected in opposite directions in parallel with
A reference resistor R having a function as a reference load is connected between the two, and both ends of the reference resistor R are connected to the positive and negative voltage output units C and B.

The positive and negative voltage output sections C and B are connected to the positive and negative output IC 71,
The positive and negative voltage output transformers 73 and 83 are connected to 81 via the positive and negative voltage output transistors 72 and 82, respectively, and capacitors c, c, c and c are connected to the positive and negative voltage output transformers 73 and 83, respectively.
It is connected to the reference resistor R via the rectifying diodes d, d, d, d.

The overvoltage control unit 2 connects both ends of the reference resistor R and one of the input terminals 12 via voltage dividing resistors 21 and 22, respectively, and both ends of the reference resistor R and the voltage dividing resistors 21 and 22. The connection points with and are connected to the positive / negative output ICs 71 and 81 via the voltage follower 23 and the inverting output operational amplifier 24, respectively, to control the excessive output voltage.

The power supply voltage detection unit 3 includes the input terminals 11 and 12
Between them with ladder resistors 31, 32, 33, 34, and relays 35, 36 in parallel with resistors 32, 33 respectively, and operate the terminal of relay 35 near the input terminal 11 via voltage follower 37. -Connected to the control unit 6.

The positive and negative current detection units 5 and 4 connect the positive and negative voltage output units C and B and one of the input terminals 12 respectively to current detection resistors.
51 and 41, and connect the positive and negative voltage output sections C and B and the current detection resistors 51 and 41 to the voltage follower.
It is connected to the operation / control unit 6 via 52, 42 and the operational amplifier 43.

The operation / control section 6 includes two D / A converters 61, 6
A digital input device (not shown) such as a keyboard is connected to the input side of 2 through the input terminal group 63, and
The voltage follower 52 of the negative current detector 4 is connected to the input side of the D / A converter 61, the output side is connected to the non-inverting input terminal of the operational amplifier 54 via the operational amplifier 53, and the other D / A converter is connected.
The voltage follower 42 of the positive current detection unit 5 is connected to the input side of 62 via the operational amplifier 43, and the output side is connected to the non-inverting input terminal of the operational amplifier 38 and the inverting input terminal of the operational amplifier 44. The voltage follower 37 of the power supply voltage detector 3 is connected to the inverting input terminal.

The output terminals of the operational amplifiers 44 and 54 are connected to the positive output IC 71, and the output terminal of the operational amplifier 38 is connected to the negative output IC 81 via the operational amplifier 39.

The operational amplifiers 38 and 54 are differential amplifiers, and output a voltage proportional to the difference between the voltages input to the inverting input terminal and the non-inverting input terminal to the positive and negative voltage output sections C and B.

With this configuration, the digital signal input from the input device to the D / A converters 61 and 62 is converted into an analog voltage, and the analog voltage and the voltage follower 37 are supplied.
The output voltage of is calculated by the operational amplifiers 38 and 54 and output to the positive and negative output ICs 71 and 81. Based on the same output, the positive and negative output ICs 7
By controlling the output from the positive and negative voltage output transformers 73 and 83 from 1,81, that is, the output voltage of the positive and negative voltage output units C and B, the detected voltage of the power supply voltage detection unit 3 and the voltage calculated above are It is controlled to be equal.

In order to control the output voltage of the positive and negative voltage output transformers 73 and 83, in addition to changing the duty ratio of the pulse wave output by the positive and negative output ICs 71 and 81, the voltage, the frequency and the pulse wave are changed. There is a means for changing the voltage change rate.

In the figure, 90 is a 24V DC power source, and 91 and 92 are 5V.
Is a positive / negative DC power source, 93, 94 are protection diodes, 95 is a pass capacitor, 96, 97, 97 are trigger terminals and transistors for turning ON / OFF the positive / negative output ICs 71, 81.

Next, the operation of the load condition setting device L for power supply characteristic inspection of the present invention will be described with reference to FIGS. 1 and 2.

With the configuration shown in FIG. 1, the voltage V1 of the power supply voltage detector 3 is proportional to the output voltage of the power supply A, and the voltages V2 and V3 of the positive and negative current detectors 5 and 4 are the negative and positive voltage output portions B and B, respectively. C
Is proportional to the current flowing through.

In particular, by switching the connections of the relays 35 and 36 and changing the voltage division ratio of the power supply voltage detection section 3, it is possible to apply to a wide range of power supply voltage and widen the range of load condition setting. You can

The power supply device A to be inspected has a positive output and a negative output, and further has a constant current system and a constant voltage system. The diodes D1 and D2 and the power supply voltage detecting section shown in FIG. When the power supply device A to be inspected has a positive output, the voltage V2 detected by the positive current detection unit 5 connected to the negative voltage output unit B is the power supply voltage detection unit due to the action of 3 and the positive and negative current detection units 5 and 4. When the voltage is lower than the voltage V1 detected by 3, the negative voltage output section B generates an output, and the voltage V2 detected by the positive current detection section 5 connected to the negative voltage output section B is detected by the power supply voltage detection section 3. When the voltage V1 is higher than the voltage V1, the positive voltage output unit C generates an output, and conversely, when the power supply device A to be tested has a negative output, the voltage V3 detected by the negative current detection unit 4 is the power supply voltage detection unit. 3 is smaller than the voltage V1 detected by the positive voltage output section C, the positive voltage output section C produces an output, and the negative current detection section 4 detects it. When the output voltage V3 is higher than the voltage V1 detected by the power supply voltage detection unit 3, the negative voltage output unit B generates an output.

In the reference state in which there is no input from the operation / control unit 6, the positive and negative voltage output units C and B do not output, and when the power supply device A has a positive output, the voltage V1 of the power supply voltage detection unit 3 and the positive voltage are positive. The voltage V2 of the current detector 5 is equal, and when the power supply A has a negative output, the power supply voltage VA and the voltage V3 of the negative current detector 4 are equal.

Next, load condition setting for each type of power supply device A will be described with reference to FIGS. 3 and 4.

When the power supply device A lowers the reference resistance R by the positive output constant current method, the action of the diodes D1 and D2 causes
The output current of power supply A is: power supply A → diode D2 →
Since the circuit of the negative voltage output unit B → the positive current detection unit 5 → the power supply device A is formed, it can be expressed by the equivalent circuit shown in FIG.

Then, when the voltage V2 of the positive / negative current detecting unit 5 is reduced by inputting from the input device to the operation / control unit 6, the above-mentioned condition, that is, the positive current detecting unit 5 is higher than the voltage V1 of the power supply voltage detecting unit 3. Since the voltage V2 becomes smaller, the negative voltage output section B outputs and the output voltage VB is generated, and the voltage obtained by adding the power supply voltage VA and the output voltage VB across the reference resistor R acts to increase the current IA. However, since the power supply device A is of the constant current system, the power supply voltage VA decreases to keep the current IA constant, and finally stabilizes in the state of V2 = V1.

In this stable state, the voltage acting across the reference resistor R is equal to the power supply voltage VA in the reference state, and
The current IA is constant, but the power supply voltage VA is reduced, that is, the resistance value of the reference resistor R is reduced.

Even when the power supply device A lowers the reference resistance R by the positive output constant voltage method, if the voltage V2 of the negative current detection unit 4 is reduced by the input from the input device, the negative voltage output unit B is caused by the condition described above. Output and the output voltage VB is generated,
The current IA increases due to the voltage generated by applying the power supply voltage VA and the output voltage VB across the reference resistor R, but since the power supply device A is a constant voltage system, the voltage VA of the power supply voltage detection unit 3 is constant. Since only the current IA increases, the voltage V2 of the positive current voltage detector 5 rises and finally stabilizes in the state of V2 = V1.

The stable state is the same state as the resistance value of the reference resistor R decreases because the current IA increases for a constant power supply voltage VA.

When the power supply device A raises the reference resistance R by the positive output constant current method, the negative voltage output section B does not output,
Since a circuit of positive voltage output unit C → reference resistance R → negative current detection unit 4 → power supply device A is additionally formed, it can be represented by an equivalent circuit shown in FIG.

When the relays 35 and 36 are switched to reduce the voltage V1 of the power supply voltage detection unit 3, the above-mentioned condition, that is, the negative current detection unit 4 is lower than the voltage V1 of the power supply voltage detection unit 3.
, The output voltage VC is generated from the positive voltage output portion C, the current from the positive voltage output portion C is added to the current flowing through the reference resistor R, and the current from the power supply device A is increased by that amount.
Although IA decreases, since the power supply device A is a constant current type, the power supply voltage VA rises and stabilizes in the state of V1−V2 = V3.

This stable state is the same as the increase in the reference resistance R because the current IA is constant despite the increase in the power supply voltage VA.

As shown in FIG. 5, the relays 35 and 36 are connected to an input device via a switching input terminal 64, and perform a switching operation by a signal from the input device.

Even when the power supply device A increases the reference resistance R by the positive output constant voltage method, if the voltage V1 of the power supply voltage detection unit 3 is reduced, the output voltage VC is generated from the positive voltage output unit C, and the positive voltage is increased. The current from the output section C is added to the current flowing through the reference resistor R, but since the power supply device A is a constant voltage system, the current IA from the power supply device A is reduced accordingly, and the power supply voltage VA is constant. Therefore, the same state as that in which the reference resistance R is increased is obtained.

As described above, the power supply device A performs positive output and increases or decreases the resistance value of the reference resistor R, which is a reference load in the constant current and constant voltage system, by operating the input device and switching the relays 35 and 36. You can

The case where the power supply A has a positive output has been described above. However, when the power supply A has a negative output, the voltage V3 of the negative current detection unit 4 is lowered when the set resistance value is made lower than the reference resistance R. When the voltage is lower than the voltage V1 of the power supply voltage detection unit 3, the positive voltage output unit C outputs the voltage, and when the set resistance value is increased, the voltage V3 of the negative current detection unit 4 is the voltage of the power supply voltage detection unit 3.
When it is greater than V1, the negative voltage output section B is caused to output, so that the setting of the reference load can be changed as in the case of positive output.

[0042]

According to the present invention, a reference resistor, a power supply voltage detection unit, a negative voltage output unit in which a positive current detection unit is connected in series, and a negative current detection are provided between input terminals connected to a power supply device. Parts in series with the positive voltage output part connected in series,
The operation / control unit is connected to each of the positive / negative voltage output unit, and the positive / negative voltage output unit is based on the detection output of the power supply voltage detection unit, the positive current detection unit and the negative current detection unit and the input from the operation / control unit. Since it is configured to control the output of the power supply, it can automatically respond to any output type power supply at the time of output characteristic inspection, and can switch the reference resistance when changing or setting the load condition for the power supply. It is easy to operate with no need for operation, and noise is not generated when changing the settings, so that the inspection work can be completed in a short time.

Further, since the power supply voltage detection section is composed of a plurality of relays connected to the connection points of a plurality of resistors connected in series between the input terminals, even if the relays are switched, a wide range of range can be obtained. The load condition can be set, and the following problems can be solved.

That is, when the setting range of the load condition is widened, it is possible to set the resistance value of the reference load only in the direction of lowering it. In this case, the resistance value of the reference load is set to the maximum required resistance value. Or, it is necessary to switch and use several kinds of reference resistors according to the application, and conversely, it is possible to set only in the direction of increasing the resistance value of the reference load,
In this case, it is necessary to set the resistance value of the reference load to the minimum required resistance value or to switch and use several kinds of reference resistors according to the application, and surges and noise will occur when switching the reference resistors. The output of the power supply device must be stopped once, and the reference resistance must be switched during that time, which causes a problem that it takes time and effort.

Further, if the setting range of the load condition is widened without switching the resistance of the power supply voltage detection unit, a positive and negative voltage output of several tens to several hundreds of watts is output with respect to the load condition setting of the power supply device of several watts. However, there is a problem that the load setting device becomes large in size because it requires the output of a section.

Further, since voltage followers are respectively provided between the output terminals of the power supply voltage detection unit, the positive current detection unit and the negative current detection unit and the operation / control unit, the voltage can be detected without affecting the detection target. Since the power supply voltage and the output voltage of the positive / negative voltage output unit can be accurately detected, the output voltage of the positive / negative voltage output unit can be accurately controlled and the load condition setting accuracy can be improved.

Further, the operation / control section is equipped with a D / A converter, and the positive / negative voltage output section can be controlled by a digital signal input from the outside, so that the input operation for setting the load condition can be performed easily and accurately. Can be done.

Further, since the positive / negative voltage output section is composed of the positive / negative voltage output transformer and the high-voltage rectifying diode, the drive circuit of the transformer can be composed of a low withstand voltage transistor or IC.

As described above, since the load condition setting device operates properly even if the polarity of the power supply device is reversed, the load condition setting device can be applied not only to positive and negative outputs but also to an AC type power supply device. Since the load can be set via the D / A converter in addition to the discrimination, it can be used for the load setting of the automatic inspection by the computer.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a load condition setting device for power supply characteristic inspection according to the present invention.

FIG. 2 is an equivalent circuit diagram of a load condition setting device.

FIG. 3 is an equivalent circuit diagram of a load condition setting device.

FIG. 4 is an equivalent circuit diagram of a load condition setting device.

FIG. 5 is an explanatory diagram of a connection state of a relay.

[Explanation of symbols]

 A power supply device B negative voltage output part C positive voltage output part d rectifier diode L load condition setting device R reference resistance 3 power supply voltage detection part 4 negative current detection part 5 positive current detection part 2 overvoltage control part 6 operation / control part 11 input Terminal 12 Input terminal 31… Resistance 35… Relay 37,42,52 Voltage follower 61,62 D / A converter 73,83 Positive / negative voltage output transformer

Claims (5)

[Claims] 1. An input terminal (11) (1) connected to a power supply (A)
Between 2), the reference resistance (R), the power supply voltage detection unit (3), and the negative voltage output unit (B) in which the positive current detection unit (5) is connected in series,
Connect the negative current detection unit (4) in series with the positive voltage output unit (C), and connect the operation / control unit (6) to the positive and negative voltage output units (C) and (B) respectively. , The power supply voltage detector (3), the positive current detector (5) and the negative current detector (4) based on the detection output and the input from the operation / control unit (6), the positive and negative voltage output unit (C ) (B) A load condition setting device for power supply characteristic inspection, which is configured to control the output. 2. The power supply voltage detection section (3) is provided with the input terminal (1
2. The power supply characteristic test according to claim 1, characterized in that it comprises a plurality of relays (35) connected to a connection point of a plurality of resistors (31) connected in series between 1) and (12). Load condition setting device. 3. A power supply voltage detector (3), a positive current detector (5)
The power supply according to claim 1, wherein voltage followers (37) (42) (52) are respectively provided between the output end of the negative current detection unit (4) and the operation / control unit (6). Load condition setting device for characteristic inspection. 4. The operation / control section (6) has a D / A converter (61) (62).
2. The load condition setting device for power supply characteristic inspection according to claim 1, further comprising: a digital signal input from the outside so that the positive and negative voltage output sections (C) and (B) can be controlled. 5. The positive / negative voltage output section (C) (B) is composed of a positive / negative voltage output transformer (73) (83) and a rectifying diode (D1) (D2), respectively. The load condition setting device for the power supply characteristic inspection described.