JP2001056353A - Inspection method for power conversion efficiency of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inspection method, for the power conversion efficiency of an electronic component, in which the number of testers can be reduced when the power conversion efficiency of the electronic component is inspected, in which measuring items are reduced, in which the inspection time can be shortened, in which costs required for an inspection are reduced and in which the electronic component can be made low-cost. SOLUTION: By a changeover circuit 1 for constant-voltage sources 11 to 13 in which at least two kinds of input voltages are fixed respectively, the constant-voltage sources are supplied to the input terminal 51 of an electronic component 5, and a current measuring circuit 2 which measures a current flowing to the input terminal 51 by the constant-voltage sources 11 to 13 is connected to the side of the input terminal 51. In addition, a constant-current source 4 and a voltage measuring circuit 3 which measures the voltage of the output terminal 51 of the electronic component 5 are connected to the output terminal 52. Then, a current value on the side of the output terminal 52 is made constant, and only an input current by the current measuring circuit 2 and only an output voltage by the voltage measuring circuit 3 are measured. Thereby, the power conversion efficiency of the electronic component 5 is found so as to be inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting power conversion efficiency, which is one of the characteristic specifications of electronic components. More specifically, the present invention relates to a method for inspecting power conversion efficiency of an electronic component, which can minimize an item to be measured and can perform an inspection in a short time and reliably.

[0002]

2. Description of the Related Art Conventionally, there is an inspection item for power conversion efficiency as one of the characteristic specifications of an electronic component. In order to inspect the power conversion efficiency, for example, as shown in FIG. 2, an input power supply 92 is connected to an input terminal 91 of an electronic component 90, and an input current measuring circuit 93 and an input voltage measuring circuit 94 are connected.
An output current measuring circuit 97 and an output voltage measuring circuit 98 are connected to the output terminal 95, respectively. Here, the current measurement circuit or voltage measurement circuit refers to the case where an ammeter or voltmeter is directly connected, the case where the current is converted to voltage and measured by a voltmeter, or the case where the voltage is divided or divided according to the scale of the meter. This includes the case where the meter is connected via a circuit or the like that performs the operation. The input voltage V _i , the input current I _i ,
The output voltage V _o and the output current I _o are measured for four items and are calculated by the following equation (1). Conversion efficiency = V _o · I _o / (V _i · I _i ) × 100 (%) (1) The reason for calculating the conversion efficiency by measuring four items at a time as described above is as follows for one product. Central value of 141V
It is necessary to inspect the power conversion efficiency at different voltages, such as around three points, near the maximum value of 170 V, and near the minimum value of 113 V, and the input voltage must be changed at the time of measurement. Therefore, the conversion efficiency is not always constant, and accurate conversion efficiency cannot be measured unless measurement is performed one by one. When the input voltage is changed in any number of ways as described above, a method of changing the input power supply 92 by a volume or switching a voltage source formed so as to have a substantially predetermined voltage by a switching circuit is used. .

[0003]

In the conventional method for inspecting the power conversion efficiency of an electronic component, as described above, both the voltage and the current are measured on both the input side and the output side, and the power is calculated by the product. The ratio is calculated. Therefore, there is a problem that one test requires measurement of four items, a long measurement time is required, and four testers for measuring voltage and current are required, resulting in an increase in cost.

On the other hand, as described above, for example, the input voltage is often specified to be a substantially constant voltage according to its specifications. Therefore, as an inspection circuit of the same product, for example, the above-mentioned three types of voltages may be always applied. By using a fixed constant voltage source, a constant predetermined voltage can be obtained without measuring each voltage. Can be applied.

[0005] The present invention has been made based on such knowledge, and when inspecting the power conversion efficiency of electronic components,
Provided is a method for inspecting the power conversion efficiency of an electronic component, in which the number of testers is reduced, the number of measurement items is reduced, the inspection time is shortened, the cost required for the inspection is reduced, and the electronic component is made inexpensive. The purpose is to:

[0006]

According to the present invention, there is provided a method for inspecting the power conversion efficiency of an electronic component, wherein the conversion efficiency of the output power with respect to the input power of the electronic component is within a predetermined range for at least two types of input voltages. A method of checking whether the at least two types of input voltages are supplied to the input terminals of the electronic component by a fixed constant voltage source switching circuit and flowing to the input terminals by the constant voltage sources. A current measuring circuit for measuring a current is connected to the input terminal side, a constant current source and a voltage measuring circuit for measuring a voltage of the output terminal are connected to an output terminal of the electronic component, and a current value of the output terminal side is measured. The power conversion efficiency is obtained by measuring only the input current by the current measurement circuit and the output voltage by the voltage measurement circuit, and the inspection is performed. .

Here, the current measuring circuit and the voltage measuring circuit are used when an ammeter or a voltmeter is directly connected, when a current is converted into a voltage and measured by a voltmeter, or when a voltage is divided according to the scale of the meter. And a case where the meter is connected via a circuit for shunting. Further, to make the current value on the output terminal side constant includes, when the value is changed according to the switching of the input voltage, to be constant for each voltage.

By using this method, the voltage of the input power is always a constant voltage, the input power can be known by measuring only the input current, and the output current of the output power is always determined by the constant current source. Can be constant,
The output power can be known by measuring only the output voltage. Therefore, (output current / input voltage) is calculated in advance and set as a constant A, and the power conversion efficiency can be easily obtained by calculating the constant A × output voltage V _o ÷ input current I _i .

[0009]

Next, an inspection method according to the present invention will be described with reference to the drawings. The method for inspecting the power conversion efficiency of an electronic component according to the present invention is a method for inspecting whether or not the conversion efficiency of output power with respect to input power of an electronic component is within a predetermined range for at least two types of input voltages. At least two types of input voltages are supplied to the input terminal 51 of the electronic component 5 as constant voltage sources fixed by the switching circuit 1, respectively.
13 connects the current measuring circuit 2 for measuring the current flowing to the input terminal 51 to the input terminal 51 side. The output terminal 52 of the electronic component 5 is connected to the constant current source 4 and its output terminal 52.
Is connected to a voltage measurement circuit 3 for measuring the voltage of the first voltage. And
The current value on the output terminal 52 side is kept constant, and only the input current by the current measuring circuit 2 and the output voltage by the voltage measuring circuit 3 are measured, so that the power conversion efficiency is obtained and the inspection is performed.

In the example shown in FIG. 1, the switching circuit 1 of the constant voltage source is connected to an output voltage control circuit 81 of an external constant voltage power supply 8 via terminals 14 and 15, and has a variable resistor for adjustment. Different constant voltage sources 11 each fixed by the unit 18
To 13 and the terminal 1 from the output terminal 82 of the constant voltage power supply 8
6 and 17 are output. For example, a constant voltage source 11 having a maximum voltage of 170 V, for example, 141
A constant voltage source 12 having a center value of V, for example, a constant voltage source 13 having a minimum voltage of 113 V is formed by a variable resistor 18 or the like, and each voltage can be switched by a switch 19, and the constant voltage is constant. The voltage is output from the output terminal 82 of the voltage power supply 8 via the terminals 16 and 17. This terminal 16 is the input terminal 5 of the electronic component 5.
1 and the terminal 17 is connected to the ground via the current measuring circuit 2.

The current measuring circuit 2 is configured so that a resistor 21 is inserted between the terminal 17 and the ground, converted into a voltage at both ends, and measured (current is measured by a voltmeter). In this example, the potential at both ends of the resistor 21 is
3 and the peripheral resistors 24 to 28, a differential amplifier is formed. A voltmeter 24 is connected as a tester between the output of the operational amplifier 23 and the ground, and a current is obtained from the measured value. . The configuration of the current measuring circuit may be such that an ammeter is connected in series without taking such a configuration, or another configuration may be adopted.

In the example shown in FIG. 1, the voltage measuring circuit 3 on the output side reads out a value of 1/2 due to a tester, and outputs a value of 100 on the output side so that it can be calculated by twice the measured value.
The circuit is divided by resistors 31 and 32 of kΩ, and a tester as a voltmeter 34 can be connected to the division point via a switch 33. Also in this case, it is not necessary to adopt such a configuration, and a configuration may be employed in which a voltmeter is directly connected via a resistor. However, in this way, a circuit that can be measured according to a tester that can be used can be configured.

The constant current source 4 is a circuit for always keeping a constant current according to the input voltage so that the current on the output terminal 52 side does not have to be measured one by one. 42, and an input voltage application terminal 44 for inputting through a control operational amplifier 43 input to the base of the transistor 41 for determining a constant current. That is, by applying a predetermined voltage to the terminal 44, a load of a predetermined constant current can always be applied to the output terminal 52 side. Therefore, when the input current is measured at the above three points and the output current also changes, by setting the input voltage to the terminal 44 to change together with the switching of the input voltage, the input voltage can be changed. A corresponding constant output current can be obtained.

The switch 6 is for switching to the constant current source 4 so as not to damage the new electronic component 5 due to discharge or the like when replacing the electronic component 5, and the diode 7 prevents the current from flowing backward. Provided for protection.

Next, the principle of measuring the power conversion efficiency by the method of the present invention will be described. As described above, the power conversion efficiency is obtained by Expression (1). However, in the present invention, since the be supplied by switching the mechanically fixed circuit input voltage, the input voltage V _i is also switched each level (e.g. 170 V, 141V, 11
(3V level) at all times. Therefore, even without one by one measurement by connecting a tester, it is treated as becomes constant voltage at each level determined by the constant voltage circuit, a preset constant voltage _{V s (V s1, V s2} , V s3) it can.
As for the output current, the constant current source, always been a constant current I _s corresponding to the input voltage.

Therefore, the above-mentioned conversion efficiency equation (1) is given by
Can be replaced as follows: _{V o · I s / (V} s · I i) × 100 = T · V o / I i × 100 (%) (2) where _{T (= I s / V s} ) is a constant. Therefore, if the calculated measure only the input current I _i and the output voltage V _o according to equation (2), easily can be obtained power conversion efficiency.

[0017]

According to the present invention, when measuring the power conversion efficiency of an electronic component, the input current and the output voltage can be measured without measuring the four items of the input voltage, the input current, the output voltage, and the output current. It is easily obtained by measuring only the items. Therefore, the inspection time for the power conversion efficiency can be greatly reduced, and the number of testers for measuring them can be reduced by half, so that the cost can be significantly reduced. As a result, electronic components can be supplied at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of an embodiment for measuring power conversion efficiency in the present invention.

FIG. 2 is a configuration explanatory diagram of an example of measuring a conventional power conversion efficiency.

[Explanation of symbols]

 1 constant voltage switching circuit 2 current measurement circuit 3 voltage measurement circuit 4 constant current source 5 electronic components 8 constant voltage power supply

Claims (1)

[Claims] 1. A method for inspecting whether the conversion efficiency of output power with respect to input power of an electronic component is within a predetermined range for at least two types of input voltages, and comprising: A fixed-voltage source switching circuit is supplied to each input terminal of the electronic component by a fixed circuit, and a current measuring circuit for measuring a current flowing through the input terminal by the constant-voltage source is connected to the input terminal side. A constant current source and a voltage measuring circuit for measuring the voltage of the output terminal are connected to the output terminal of the component, and the current value on the output terminal side is made constant, and the input current by the current measuring circuit and the output by the voltage measuring circuit are output. A method for inspecting the power conversion efficiency of an electronic component, wherein the power conversion efficiency is obtained by measuring only the voltage and inspecting the electronic component.