Test circuit for capacitive product

Abstract

The utility model discloses a test circuit for a capacitive product, relates to the field of electronic component test screening equipment, and solves the problems that a traditional pointer type insulation test instrument cannot ensure the contact reliability in the test process and cannot quickly output an insulation test judgment result when the capacitive product is tested. The main points of the technical scheme are that the device comprises a clamp voltage current-limiting resistor, an operational amplifier, a relay and a programmable controller; the clamp voltage current-limiting resistor is connected with the positive input end of the operational amplifier, the output end of the operational amplifier is connected with the reverse input end of the operational amplifier, the output end of the operational amplifier is connected with the negative power supply end of the operational amplifier through the control end of the relay, and the controlled end of the relay is connected with the programmable controller and a level signal. The programmable controller is used for collecting level signals before and after time delay; a programmable controller is arranged to acquire level signals before and after time delay, so that contact reliability test and insulation test results can be quickly output.

Description

Technical Field

[0001] The utility model relates to the field of electronic component test and screening equipment, and more specifically, it relates to a test circuit for capacitive products. Background Art

[0002] The existing insulation test for capacitive products usually uses a pointer-type insulation test instrument. However, when the traditional pointer-type insulation test instrument is applied to test capacitive products in an automated device, it cannot ensure the contact reliability during the test process, which affects the accuracy of the test results. Moreover, it lacks an output port for the test result signal and cannot meet the rapid test requirements. Content of the Utility Model

[0003] The technical problem to be solved by this application is that the traditional pointer-type insulation test instrument cannot ensure the contact reliability during the test process of capacitive products and cannot collect and output the insulation test judgment result. The purpose is to provide a test circuit for capacitive products, which realizes the contact reliability test and the rapid output of the insulation test result by setting a programmable controller to collect the level signals before and after the delay.

[0004] This application is realized by the following technical solutions:

[0005] A test circuit for capacitive products includes: a clamping voltage limiting resistor, an operational amplifier, a relay, and a programmable controller; the clamping voltage limiting resistor is connected to the positive input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the negative input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the negative power supply terminal of the operational amplifier through the control terminal of the relay, the controlled terminal of the relay is respectively connected to the programmable controller and a low-level signal, and the programmable controller is used to collect the level signals before and after the delay.

[0006] With the above technical solution, when a capacitive product is reliably connected to the circuit, according to the charging characteristics of the product's capacitance, a non-conforming signal will be generated at the moment of contact. By capturing the signal state at the moment of charging, the contact reliability of the capacitive product can be determined. Specifically, the voltage signal IN generated when the pointer-type insulation test instrument is connected to the capacitive product is collected through a voltage follower. The front and rear stage voltages of the signal are isolated through a clamping current-limiting resistor and an operational amplifier. When the voltage output by the operational amplifier is greater than the threshold, the highly sensitive relay is driven to act. The level signal collected by the programmable controller is a low-level signal, and the contact reliability can be quickly determined through the low-level signal. After the capacitive product is fully charged, according to the insulation characteristics of the product's capacitance, a qualified signal will be generated. By capturing the signal state after charging is completed, the insulation of the capacitive product can be determined. Specifically, according to the different capacitances of the capacitive products, the delay time is appropriately set to ensure that the charging is completed. The programmable controller executes the delay program and collects the level signal after the delay. At this time, the voltage output by the operational amplifier is less than the threshold, and the highly sensitive relay resumes operation. The level signal collected by the programmable controller is a high-level signal, and the insulation test result can be quickly judged to be qualified through the high-level signal.

[0007] Further, the relay is an electromagnetic relay.

[0008] Further, the relay is a normally open relay. When the voltage signal at the controlled end is greater than the threshold voltage signal, the relay closes.

[0009] Further, the threshold voltage signal is 12V.

[0010] Further, the clamping current-limiting resistor includes resistor R1 and resistor R2. One end of resistor R1 is connected to the bad drive signal of the instrument detection circuit, and the other end is connected to the positive input terminal of the operational amplifier. One end of resistor R2 is connected to the positive input terminal of the operational amplifier, and the other end is grounded.

[0011] Further, both resistor R1 and resistor R2 are resistors in the order of K ohms.

[0012] Further, resistor R1 is 1K ohm and resistor R2 is 10K ohms.

[0013] Further, the low-level signal is 0V.

[0014] Further, the programmable controller is a single-chip microcomputer.

[0015] Further, the capacitive product is a chip ceramic capacitor.

[0016] Compared with the prior art, the present application has the following beneficial effects: By improving the circuit of the traditional pointer-type insulation test instrument, when a non-conforming signal is generated during the test, a 12VDC voltage is generated in the circuit loop. Through this voltage, a highly sensitive relay is driven to close. At this time, the programmable controller performs one acquisition to obtain a level signal to judge whether the contact is reliable; the programmable controller executes a delay program and performs a second acquisition to obtain a level signal to judge whether the insulation test is qualified. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, and constitute a part of this application, but do not limit the embodiments of this application. In the drawings:

[0018] Figure 1 It is a test circuit diagram for capacitive products provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To make the objectives, technical solutions, and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in combination with the embodiments and the drawings. The illustrative embodiments and descriptions thereof of the present utility model are only used to explain the present utility model and do not limit the present utility model.

[0020] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component.

[0021] It should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

[0022] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more, unless otherwise specifically defined.

[0023] Embodiment 1

[0024] Embodiment 1 provides a test circuit for capacitive products. Please refer to Figure 1 as shown in the figure, which includes a clamping current-limiting resistor, an operational amplifier, a relay, and a programmable controller. The clamping current-limiting resistor is connected to the positive input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the negative input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the negative power supply terminal of the operational amplifier through the control terminal of the relay. The controlled terminal of the relay is respectively connected to the programmable controller and a low-level signal. The programmable controller is used to collect the level signals before and after the delay.

[0025] The principle of realizing the contact reliability test in this embodiment is that when the capacitive product is reliably connected to the circuit, according to the charging characteristics of the product's capacitance, an unqualified signal will be generated at the moment of contact. The contact reliability of the capacitive product can be determined by capturing the signal state at the moment of charging. Specifically, according to the parameters set by the pointer-type insulation test instrument, when the loop current is higher than the set threshold, the bad indicator light of the instrument lights up. The input signal of this embodiment is taken from the bad indication drive signal of the instrument detection circuit. The voltage signal generated when the pointer-type insulation test instrument is connected to the capacitive product is collected through a voltage follower, realizing the voltage isolation between the front and rear stages of the high clamping current-limiting resistor with low output impedance, and at the same time improving the load-carrying capacity. When the instrument generates a bad signal output, the highly sensitive relay is driven to act. The level signal collected by the programmable controller is a low-level signal. The contact reliability can be quickly determined by collecting the low-level signal at the moment of contact.

[0026] The principle of realizing the rapid output of the insulation test result in this embodiment is that when the capacitive product is fully charged, according to the insulation characteristics of the product's capacitance, a qualified signal will be generated. The insulation of the capacitive product can be determined by capturing the signal state after the charging is completed. Specifically, according to the different capacities of the capacitive products, the delay time is appropriately set to ensure that the charging is completed. The programmable controller executes the delay program and collects the level signal after the delay. At this time, the output terminal of the voltage follower is at a low level, and the highly sensitive relay resumes action. The level signal collected by the programmable controller is a high-level signal. The insulation test result can be quickly judged to be qualified through the high-level signal.

[0027] The improvement of this solution is that by setting a special circuit structure and a programmable controller, the level signals before and after the delay are collected, realizing the detection of contact reliability and the rapid output of the insulation test result, and at the same time having the characteristic of detecting whether the acquisition loop is faulty.

[0028] It should be noted that the setting of the delay program is a prior art. The key point of this solution is to adopt a specially set circuit loop and a programmable controller with a delay program to realize the judgment of contact reliability and the output of the insulation test result.

[0029] Furthermore, the relay is an electromagnetic relay.

[0030] Furthermore, the relay is a normally open relay, which closes when the voltage signal at the controlled end is greater than the threshold voltage signal.

[0031] With the above solution, when the contact is reliable, the voltage follower outputs a signal to drive the relay to close, the programmable controller conducts a circuit with the low-level signal, and a low-level signal is collected; when the contact is unreliable, the relay disconnects under the low-level signal, the circuit between the programmable controller and the low-level signal is open-shorted, and a high-level signal is collected.

[0032] Furthermore, the threshold voltage signal is 12V.

[0033] With the above solution, when the voltage applied to the controlled end of the relay is 12V, the relay closes; when the voltage applied to the controlled end of the relay is less than 12V, the relay returns to the open state.

[0034] Furthermore, the clamping current-limiting resistor includes resistor R1 and resistor R2. One end of resistor R1 is connected to the bad driving signal IN of the instrument detection circuit, and the other end is connected to the positive input terminal of the operational amplifier. One end of resistor R2 is connected to the positive input terminal of the operational amplifier, and the other end is grounded. Its function is to divide the voltage and clamp the voltage when IN is at a high level, and pull the input terminal down to 0 when IN has no input.

[0035] Furthermore, both resistor R1 and resistor R2 are resistors in the order of K ohms.

[0036] Furthermore, resistor R1 is 1K ohm and resistor R2 is 10K ohms.

[0037] With the above solution, the front and rear stage impedance conversion is achieved through the voltage follower, the load-carrying capacity of the rear stage is increased, and voltage isolation is achieved.

[0038] Furthermore, the low-level signal is 0V.

[0039] Furthermore, the programmable controller is a single-chip microcomputer.

[0040] Furthermore, the capacitive product is a chip ceramic capacitor.

[0041] It should be noted that the test circuit provided in this embodiment improves the circuit of the traditional pointer-type insulation test instrument, so that when a non-conforming signal is generated during the test, a 12VDC voltage is generated in the circuit loop, and the high-sensitivity relay is driven to close through this voltage. At this time, the programmable controller performs one acquisition to obtain a level signal to judge whether the contact is reliable; the programmable controller executes a delay program and performs a second acquisition to obtain a level signal to judge whether the insulation test is qualified.

[0042] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present utility model. It should be understood that the above description is only for the specific embodiments of the present utility model and is not intended to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A test circuit for capacitive products, characterized in that: include: Voltage clamping and current limiting resistors, operational amplifiers, relays and programmable controllers; The clamping current limiting resistor is connected to the positive input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the reverse input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the negative power supply terminal of the operational amplifier through the control terminal of the relay, and the controlled terminal of the relay is respectively connected to the programmable controller and the low-level signal, and the programmable controller is used to collect the level signals before and after the delay.

2. A test circuit for capacitive products according to claim 1, characterized in that: The relay is an electromagnetic relay.

3. A test circuit for capacitive products according to claim 2, characterized in that: The relay is a normally open relay, and when the voltage signal at the controlled end is greater than the threshold voltage signal, the relay is closed.

4. A test circuit for capacitive products according to claim 3, characterized in that: The threshold voltage signal is 12V.

5. A test circuit for capacitive products according to claim 1, characterized in that: The clamping current limiting resistor includes a resistor R1 and a resistor R2, one end of the resistor R1 is connected to the bad driving signal of the instrument detection circuit, and the other end is connected to the positive input end of the operational amplifier, and one end of the resistor R2 is connected to the positive input end of the operational amplifier, and the other end is grounded.

6. A test circuit for capacitive products according to claim 5, characterized in that: The resistor R1 and the resistor R2 are both K-ohm resistors.

7. A test circuit for capacitive products according to claim 6, characterized in that: The resistor R1 is 1K ohm, and the resistor R2 is 10K ohm.

8. A test circuit for capacitive products according to claim 1, characterized in that: The low level signal is 0V.

9. A test circuit for capacitive products according to claim 1, characterized in that: The programmable controller is a single chip microcomputer.

10. A test circuit for capacitive products according to claim 5, characterized in that: The capacitive product is a chip-type ceramic capacitor.

Images