TWI465748B - Voltage testing device with positive and negative outputs - Google Patents

Description

Withstand voltage test device with positive and negative voltage output

The present invention relates to a withstand voltage test apparatus, and in particular to a withstand voltage test apparatus having a DC positive polarity voltage, a DC negative polarity voltage, and an AC voltage for testing an electronic device.

Today, with the development of science and technology, from personal life to the international community, electronic devices are ubiquitous. Since electronic devices are so widely used in various fields, ensuring their safe operation is an important issue. Whether it is electronic devices (such as electric heaters, hair dryers, etc.) or electronic components (such as optocouplers, capacitors, solar panels, etc.), a series of safety tests must be passed after production or before sale to confirm that they are safe. specification. If the electronic product is used without the above safety test, the product may be damaged due to sudden voltage instability, and even worse, the user's personal safety may be endangered.

The above safety test includes a withstand voltage test and an insulation test. In the withstand voltage test, the test device outputs a high voltage test voltage to the electronic component or product to be tested to test whether it can meet the withstand voltage conditions of the safety specification. Next, the test device outputs a lower insulation test voltage to the electronic component or product to be tested to test its insulation value.

Some electronic components or products, such as ceramic capacitors or solar panels, generate residual voltage after high voltage testing, and the voltage of the residual voltage is higher than that entered during high voltage testing. The voltage test voltage is proportional to the magnitude of the voltage. The subsequent insulation test is performed with a small voltage, so it may be affected by the residual voltage, resulting in excessive test error.

Referring to FIG. 1 , FIG. 1 is a schematic diagram showing voltage changes in an electronic device during a high voltage test and an insulation test in the prior art. As shown in Figure 1, the vertical axis is the voltage (V) at the time of the test and the horizontal axis is the test time (T). The curve L1 is the voltage input by the electronic device for the high voltage test, for example, the highest voltage reaches 6600 volts, and the curve L2 is the residual voltage generated by the electronic device after the high voltage test, for example, the highest residual voltage is about 1000 volts. Curve L3 is the voltage input by the electronic device for insulation testing, for example, its maximum voltage is 500 volts. It can be seen from Fig. 1 that the voltage input during the insulation test is less than the residual voltage in the partial period, and in this part of the cycle, the insulation test will show a meaningless negative current direction. In other words, the residual voltage generated by the high voltage test will seriously affect the accuracy of the insulation test.

To avoid the above residual voltage problem, the insulation test can be performed after the residual voltage disappears, but this method will increase the overall test time. In addition, voltage signals of opposite polarity can be input to the object to be tested during the insulation test to avoid residual voltage problems. Please refer to FIG. 2 . FIG. 2 is a schematic diagram showing voltage changes of voltages input with different polarities when the electronic device performs high voltage testing and insulation testing. As shown in Figure 2, if the high voltage test inputs a positive voltage and the insulation test inputs a negative voltage, since the residual voltage represented by the curve L2' is opposite to the polarity of the insulation test voltage represented by the curve L3', a meaningless negative current can be avoided. The direction affects the accuracy of the insulation test. In addition, in the safety test, if the bypass capacitance of the electronic component or product waiting for the test object is too large, the AC withstand voltage test cannot be used and the DC withstand voltage test must be used, so the test object is here. In the case of a safety test that only receives DC positive voltage. However, the object to be tested may have different test results in the negative voltage test, so the negative voltage and the AC voltage state cannot be truly simulated only with the DC positive voltage input.

In the prior art, high voltage and insulation tests of different polarities described above were performed by separate circuits. However, the independent circuit not only increases the complexity of the entire device architecture, but also increases the cost of the test device. On the other hand, the prior art also provides a positive and negative switching in a scanning manner, which will exchange the original input terminal and the ground terminal when switching between the positive and negative electrodes. For example, in a positive voltage test, the test terminal of the electronic device receives a positive voltage from the test device and the case is grounded; in the negative voltage test, the outer casing of the electronic device receives a positive voltage from the test device and the test terminal is grounded, in other words The test terminal of the electronic device is a negative voltage input with respect to the ground. However, such a negative voltage test is highly likely to be subjected to a high-voltage electric shock due to an operator accidentally touching the outer casing of the electronic device, thereby endangering personal safety.

Accordingly, it is an object of the present invention to provide a withstand voltage test apparatus having a positive and negative polarity voltage output to solve the problems of the prior art.

According to a specific embodiment, the withstand voltage test device having a positive and negative voltage output includes a signal generating module, an output end, and a switching module, wherein the switching module is electrically connected between the signal generating module and the output end. . The signal generation module can be used to generate a high voltage signal to the switching module, and the output end can be electrically connected to the object to be tested. The switching module includes a first switch or a second switch, and according to the cooperation of the first switch and the second switch, the received high voltage signal can be output as a DC positive voltage, a DC negative voltage or an AC voltage. After being sent to the output, the test object is tested.

In this embodiment, when the first switch is turned on and the second switch is open, the switching module can output the high voltage signal as a DC negative voltage and transmit to the output end; when the first switch is open and the second switch is turned on, the switching is performed. The module can output the high voltage signal as a direct current voltage and transmit to the output terminal; and when the first switch and the second switch are simultaneously turned on, the switching module can output the high voltage signal as an alternating current voltage and transmit it to the output end.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

Referring to FIG. 3, FIG. 3 is a schematic diagram showing a withstand voltage testing device 1 having a positive and negative polarity voltage output according to another embodiment of the present invention. As shown in FIG. 1 , the withstand voltage testing device 1 includes a signal generating module 10 , a switching module 12 electrically connected to the signal generating module 10 , and an output end 14 electrically connected to the switching module 12 . In addition, the withstand voltage test device 1 can further include a control module 16 electrically connected to the signal generating module 10 and the switching module 12 for controlling the operation of the signal generating module 10 and the switching module 12. The output end 14 is electrically connected to the first end of the object to be tested, and the second end of the object to be tested is electrically connected to the ground end 140 of the withstand voltage testing device 1, wherein the first end of the object to be tested Is the test end. The object to be tested may be an electronic component or product that requires high voltage testing and insulation testing, such as an electric heater, a hair dryer, an optocoupler, a capacitor, or a solar panel.

In this embodiment, the switching module 12 includes a first switch 120, The second switch 122, the first diode 124 and the second diode 126. The anode of the first diode 124 is electrically connected to the signal generating module 10, and the cathode of the second diode 126 is electrically connected to the cathode of the first diode 124 and the anode of the second diode 126. Connected to the output terminal 14. The first switch 120 is connected in parallel to the first diode 124, and the second switch 122 is connected in parallel to the second diode 126. The switching module 12 further includes a third switch 128 electrically connected to the output end 14 , and the third switch 128 is also controlled by the control module 16 to be turned on or open, and the third switch 128 and the signal generating module 10 are connected to each other. The RC filter circuit is connected in series.

The control module 16 can control the signal generating module 10 to generate a high voltage signal, and the high voltage signal can be transmitted to the switching module 12, wherein the high voltage signal is an alternating high voltage signal. Then, the control module 16 can control the first switch 120 and the second switch 122 to open or conduct. When the control module 16 controls the first switch 120 to be turned on and the second switch 122 is open, the third switch 128 is also turned on, so that the output terminal 16 is electrically connected to the RC filter circuit to filter the high voltage signal, and the high voltage signal passes through the first The diode 126 and the RC filter circuit are converted into a DC negative voltage signal and then sent to the output terminal 14, and the DC negative voltage is supplied through the output terminal 14 to the first end (test end) of the object to be tested for testing. In contrast, when the control module 16 controls the first switch 120 to open and the second switch 122 is turned on, the third switch 128 is also turned on, so that the output terminal 16 is electrically connected to the RC filter circuit to filter the high voltage signal. The signal is converted to a direct current positive voltage signal by the first diode 124 and the RC filter circuit, and is sent to the output terminal 14 through the output terminal 14, and the DC positive voltage is supplied to the first end (test end) of the object to be tested. test.

When the first switch 120 and the second switch 122 are turned on and the third switch 128 is open, the high voltage signal is transmitted to the output terminal 14 through the first switch 120 and the second switch 122, and the high voltage signal of the alternating current is provided through the output terminal 14. Test to the first end (test end) of the object to be tested. As described above, by controlling the first switch 120, the second switch 122, and the third switch 128, the high voltage signal generated by the signal generating module 10 can be directly outputted to the DC positive voltage, the DC negative voltage, and the AC voltage. The test end of the object to be tested.

Referring to FIG. 3 again, as shown in FIG. 3 , the withstand voltage testing device 1 further includes a shunt circuit 180 and a voltage dividing circuit 182 , wherein the shunt circuit 180 is electrically connected to the second end of the object to be tested (ground end) 140), the voltage dividing circuit 282 is electrically connected between the first end (output end 14) and the second end (ground end 140) of the object to be tested. The shunt circuit 180 and the voltage dividing circuit 182 are respectively configured to detect the current and the voltage of the object to be tested, and accordingly generate an analog signal of the analog current and the analog signal of the feedback voltage. The shunt circuit 180 and the voltage dividing circuit 182 can be electrically connected to the control module 16 to transmit the analog current and voltage analogy to the control module 16 for test calculation.

In the embodiment, the control module 16 further includes a control unit 160, a first conversion unit 162, and a second conversion unit 164. The first conversion unit 162 is electrically connected to the control unit 160 and the signal generation module 10. The second conversion unit 164 is electrically connected to the control unit 160 and the shunt circuit 180 and the voltage dividing circuit 182, respectively. The control unit 160 can generate the output-controlled digital signal to the first conversion unit 162. Then, the first conversion unit 162 can convert the output-controlled digital signal into an output-controlled analog signal, and then transmit the signal to the signal generation module 10, and generate the signal. Module 10 A high voltage signal can be generated based on the analog signal controlled by this output. On the other hand, the analog signals of the feedback current and voltage generated by the shunt circuit 180 and the voltage dividing circuit 182 can be converted into digital signals of the current and voltage by the second converting unit 164, and then transmitted back to the control. The unit 160 enables the control unit 160 to perform a test calculation based on the digital signals of the feedback current and voltage. In addition, the switches of the switching module 12 are also controlled by the control unit 100 in the control module 10. For example, if an operator wants to test the object to be tested with a DC positive voltage, the operation command may be sent to the control unit 100, and the control unit 100 controls the first switch 120 to open, the second switch 122, and the third switch according to the operation command. 128 is on. Moreover, the control unit 100 can control the switching module 12 by the control logic program to achieve the effect of the automatic variable voltage test.

The signal generation module 10 can receive the control of the control module 16 to generate a high voltage signal, which is described in detail below. In the specific embodiment, the signal generating module 10 further includes a sine wave generator 100, a power amplifier 102, and a high voltage transformer 104. The sine wave generator 100 is electrically connected to the first conversion unit 162 of the control module 16 to receive an analog signal of the output control from the first conversion unit 162, and accordingly generate a sine wave. The power amplifier 102 is electrically connected to the sine wave generator 100, which can generate a driving signal according to a sine wave generated by the sine wave generator 100. The high voltage transformer 104 is electrically connected to the power amplifier 102 and the switching module 12 to receive the driving signal from the power amplifier 102 and convert the driving signal into a high voltage signal and output the signal to the switching module 12.

Referring to FIG. 4, FIG. 4 is a schematic diagram showing a withstand voltage testing device 2 having a positive and negative polarity voltage output according to another embodiment of the present invention. As shown in FIG. 4, this specific embodiment is different from the above specific embodiment in The anode of the first diode 224 of the switching module 22 of the present embodiment is electrically connected to the output terminal 24 , and the cathode of the second diode 226 is electrically connected to the output terminal 24 . In addition, the first switch 220 of the switching module 22 is electrically connected between the signal generating module 20 and the negative pole of the first diode 224, and the second switch 222 is electrically connected to the signal generating module 20 and the second Between the positive poles of the polar body 226. The other units of the withstand voltage test apparatus 2 of the present embodiment are substantially the same as the corresponding units of the withstand voltage test apparatus 1 of the above specific embodiment, and thus will not be described again.

In the embodiment, when the control module 26 controls the first switch 220 to be turned on, the second switch 222 to be open, and the third switch 228 to be turned on, the high voltage signal generated by the signal generating module 20 passes through the first diode 224 and The negative voltage signal converted to DC after the RC filter circuit is transmitted to the output terminal 24. On the other hand, when the control module 26 controls the first switch 220 to open, the second switch 222 is turned on, and the third switch 228 is turned on, the high voltage signal is converted into a direct current positive voltage signal after passing through the second diode 226 and the RC filter circuit. Transfer to output 24. In addition, when the control module 26 controls the first switch 220 and the second switch 222 to be turned on and the third switch 228 is open, the alternating high voltage signal passes through the first switch 220, the second switch 222, the first diode 224, and the second. The diode 226 is passed to the output terminal 24. Please note that in another embodiment, the first switch 220 can also be disposed between the first diode 224 and the output terminal 24, and the second switch 222 can also be disposed at the second diode 226 and the output end. Between 24, a DC positive voltage, a DC negative voltage or an AC voltage can also be output to the output terminal 24 by the control of the previous embodiment.

In summary, the withstand voltage test device of the present invention can input a DC positive voltage, a DC negative voltage or an AC voltage through the first end (test end) of the device to be tested through the switching module, so that the withstand voltage test device can perform the object to be tested. Straight after high voltage test The insulation test is conducted with the test voltage of the opposite polarity to avoid the residual voltage generated after the high voltage test affecting the accuracy of the insulation test. On the other hand, compared with the prior art method of performing positive and negative switching in a scanning manner, since the withstand voltage test device of the present invention maintains the second end (ground terminal) of the object to be tested at a low potential, it is not caused by changing the test signal. The polarity of the object to be tested has a high voltage voltage to prevent the operator from being shocked by accidentally touching the high voltage housing, further providing a safe test environment. In addition, the withstand voltage test device of the present invention provides a DC positive voltage, a DC negative voltage or an AC voltage in a single circuit instead of a separate circuit, so that the device architecture is simplified and uncomplicated, and the cost of the test device can be reduced.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed. Therefore, the scope of the patented scope of the invention should be construed as broadly construed in the

L1, L2, L3, L1', L2', L3'‧‧‧ curves

1, 2‧‧‧ Withstand voltage test device with positive and negative voltage output

10, 20‧‧‧ Signal Generation Module

12, 22‧‧‧Switch Module

14, 24‧‧‧ Output

16, 26‧‧‧Control Module

100, 200‧‧‧ sine wave generator

102, 202‧‧‧ power amplifier

104, 204‧‧‧ high voltage transformer

120, 220‧‧‧ first switch

122, 222‧‧‧ second switch

124, 224‧‧‧ first diode

126, 226‧‧‧ second diode

128, 228‧‧‧ third switch

140, 240‧‧‧ Grounding

160, 260‧‧‧ control unit

162, 262‧‧‧ first conversion unit

164, 264‧‧‧ second conversion unit

180, 280‧‧ ‧ shunt circuit

182, 282‧‧ ‧ voltage divider circuit

FIG. 1 is a schematic diagram showing voltage changes during the high voltage test and the insulation test of the electronic device in the prior art.

FIG. 2 is a schematic diagram showing changes in voltages of different polarity voltages when the electronic device performs high voltage testing and insulation testing.

FIG. 3 is a schematic diagram showing a withstand voltage test apparatus having a positive and negative polarity voltage output according to another embodiment of the present invention.

4 is a schematic diagram showing a withstand voltage test apparatus having a positive and negative polarity voltage output according to another embodiment of the present invention.

1‧‧‧Withstand voltage test device with positive and negative voltage output

10‧‧‧Signal Generation Module

12‧‧‧Switch Module

14‧‧‧ Output

16‧‧‧Control Module

100‧‧‧Sine wave generator

102‧‧‧Power Amplifier

104‧‧‧High voltage transformer

120‧‧‧First switch

122‧‧‧Second switch

124‧‧‧First Diode

126‧‧‧second diode

128‧‧‧third switch

140‧‧‧ Grounding terminal

160‧‧‧Control unit

162‧‧‧First conversion unit

164‧‧‧Second conversion unit

180‧‧‧Split circuit

182‧‧‧voltage circuit

Claims (9)

A voltage withstand test device having a positive and negative voltage output includes: a signal generating module for generating a high voltage signal; and an output terminal for electrically connecting a first end of the object to be tested, and the object to be tested The second end is electrically connected to a ground end; and a switching module is electrically connected between the signal generating module and the output end for receiving the high voltage signal to output a constant current and a constant current The switching module includes a first switch and a second switch; wherein, when the first switch is turned on and the second switch is open, the switching module transmits the DC negative voltage to the output End, when the first switch is open and the second switch is turned on, the switching module transmits the DC positive voltage to the output end, and when the first switch and the second switch are simultaneously turned on, the switching module will The AC voltage is delivered to the output. The voltage-testing device of claim 1, wherein the switching module further comprises: a first diode, the anode of the first diode is electrically connected to the signal generating module; a second diode, the cathode of the second diode is electrically connected to the cathode of the first diode, and the anode of the second diode is electrically connected to the output terminal; wherein the first switch Parallel to the first diode, the second switch is connected in parallel to the second diode. The pressure test device of claim 1, wherein the switch module further comprises: a first diode, the anode of the first diode is electrically connected to the output end; and a second diode, the cathode of the second diode is electrically connected to the output end; wherein The first switch is electrically connected between the signal generating module and the negative electrode of the first diode, and the second switch is electrically connected between the signal generating module and the positive electrode of the second diode. The voltage-testing device of claim 1, wherein the switching module further comprises: a third switch electrically connected to the output end; and a filter circuit electrically connected to the The third switch is connected to the signal generating module; wherein when the first switch and the second switch are simultaneously turned on, the third switch is open. The pressure test device of claim 1, further comprising: a control module electrically connected to the signal generating module and the switching module, wherein the control module is configured to control the switching module, And generating an analog signal of the output control to drive the signal generating module and detecting the current or voltage of the object to be tested. The voltage test device of claim 5, wherein the signal generating module comprises: a sine wave generator electrically connected to the control module, the sine wave generator is based on an analogy of the output control The signal generates a sine wave; a power amplifier is electrically connected to the sine wave generator, the power amplifier generates a driving signal according to the sine wave; and a high voltage transformer is electrically connected to the power amplifier, and the high voltage is transformed The device converts the driving signal into the high voltage signal. The pressure test device of claim 5, wherein the control module comprises: a control unit for generating an output controlled digital signal; a first conversion unit electrically connected to the control unit; The first conversion unit is configured to convert the digital signal of the output control into an analog signal of the output control; and a second conversion unit is electrically connected to the control unit, and the second conversion unit is configured to send a feedback current Converting the analog signal into a digital signal of a current feedback, and converting the analog signal of a feedback voltage into a digital signal of a feedback voltage; wherein the control unit is based on the digital signal of the feedback current or the feedback The digital signal of the voltage is tested and calculated. The voltage test device of claim 7, further comprising: a shunt circuit electrically connected to the second end of the object to be tested, wherein the shunt circuit is configured to detect the current of the object to be tested to generate The analog signal of the feedback current. The pressure test device of claim 7, further comprising: a voltage dividing circuit electrically connected between the first end and the second end of the object to be tested, wherein the voltage dividing circuit is used The voltage of the test object is detected to generate an analog signal of the feedback voltage.