A relay detection circuit

Abstract

The utility model relates to relay detection field, the utility model relates to a relay detection circuit, include: power supply circuit, its output end is connected to the input of voltage conversion circuit, is used for providing direct current voltage for voltage conversion circuit, voltage conversion circuit is used for converting the size of direct current voltage of power supply circuit output, coil detection circuit, include: first wiring terminal, second wiring terminal, voltage transformer, its secondary side is connected to CPU controller's AD sampling port, current transformer, its secondary side passes through sampling resistance and is connected to CPU controller's AD sampling port, CPU controller, its IO pin is connected to nixie tube, contact detection circuit, include: third wiring terminal, fourth wiring terminal, in turn connect first emitting diode and first grounding resistance after grounding, still be used for connecting the other contact of relay's contact pair. Adopt the relay detection circuit of the utility model can effectively improve the detection efficiency and detection accuracy when detecting relay.

Description

Technical Field

[0001] This utility model relates to the field of relay detection. More specifically, this utility model relates to a relay detection circuit. Background Technology

[0002] A relay is a common electromagnetic control component widely used in household appliances, power systems, industrial control, and communications. When an internal coil is energized, it generates electromagnetic attraction, which drives the contacts to close or open, thereby controlling the on / off state of a circuit.

[0003] In the field of power distribution, the output circuit of secondary protection devices is a crucial function, determining whether the power circuit is correctly controlled. Relays are typically installed in the output circuit of secondary protection devices, making it essential to verify their proper functioning before soldering them into the output circuit.

[0004] Existing relay testing methods include testing the relay coil and the relay contacts. Relay coil testing typically relies on manual measurement of the coil's voltage and current at a single point using a multimeter or specialized testing equipment. The coil's resistance is then calculated manually; if the resistance is within the normal range, the relay coil is considered normal. For relay contact testing, a power supply and an indicator light are connected in series across the contacts, and the contact closure is determined by observing whether the indicator light is on or off. This existing testing method has the following drawbacks:

[0005] (1) The detection process is cumbersome and requires manual intervention, making it difficult to automate;

[0006] (2) The detection efficiency is low and cannot meet the needs of rapid screening and detection of a large number of relays;

[0007] (3) Measurement results are easily affected by manual reading or calculation errors, resulting in low detection accuracy;

[0008] (4) Lack of accurate detection and intuitive display of coil resistance.

[0009] In summary, existing relay detection methods suffer from low detection efficiency and accuracy, and cannot provide a direct display of coil resistance values. Utility Model Content

[0010] To address the problems of low detection efficiency and accuracy, and the inability to intuitively display coil resistance values ​​in existing relay detection methods, this invention provides solutions in the following aspects.

[0011] In a first aspect, the present invention provides a relay detection circuit, comprising:

[0012] The power supply circuit has its output terminal connected to the input terminal of the voltage conversion circuit to provide DC voltage to the voltage conversion circuit.

[0013] A voltage conversion circuit is used to convert the magnitude of the DC voltage output by the power supply circuit;

[0014] The coil detection circuit includes: a first terminal block connected to the output of a voltage conversion circuit and also used to connect the first end of a relay coil; a second terminal block grounded and also used to connect the second end of a relay coil; a voltage transformer for acquiring the voltage across the relay coil, with its secondary side connected to the AD sampling port of the CPU controller; a current transformer for acquiring the current flowing through the relay coil, with its secondary side connected to the AD sampling port of the CPU controller via a sampling resistor; and a CPU controller whose I / O pins are connected to a digital display for calculating the resistance of the relay coil based on the voltage across the relay coil and the current flowing through the relay coil, and displaying the value on the digital display.

[0015] The contact detection circuit includes: a third terminal block, which is connected to the output of the power supply circuit and is also used to connect one of the contacts of the relay contact pair; and a fourth terminal block, which is connected to the ground in series with the first light-emitting diode and the first grounding resistor, and is also used to connect the other contact of the relay contact pair.

[0016] Preferably, the voltage conversion circuit includes a DC / DC converter, whose input terminal is connected to the output terminal of the power supply circuit, and whose output terminal is connected to the first fixed terminal and the sliding terminal of the sliding rheostat, respectively. The second fixed terminal of the sliding rheostat is the output terminal of the voltage conversion circuit.

[0017] Preferably, the output terminal of the DC / DC converter is connected to ground in series with a second grounding resistor and a second light-emitting diode.

[0018] Preferably, the output terminal of the DC / DC converter is grounded through a first filter capacitor.

[0019] Preferably, the output of the DC / DC converter is grounded through a Zener diode.

[0020] Preferably, the power supply circuit includes a USB power supply port and a battery pack. The positive terminal of the USB power supply port is connected to the first terminal of the first switch, the second terminal of the first switch is connected to the input terminal of the voltage conversion circuit, and the positive terminal of the battery pack is connected to the input terminal of the voltage conversion circuit through a second switch.

[0021] Preferably, a first diode is connected in series between the second switch and the input terminal of the voltage conversion circuit, wherein the anode of the first diode is connected to the second switch and the cathode is connected to the input terminal of the voltage conversion circuit.

[0022] Preferably, the negative terminal of the USB power supply port is connected to the first terminal of the first transient suppression diode, the second terminal of the first transient suppression diode is connected to the second terminal of the first switch, and grounded through the second filter capacitor; the negative terminal of the battery pack is grounded and connected to the anode of the first diode through the second transient suppression diode.

[0023] Preferably, the anode of the first diode is connected to the fourth terminal via a push-button switch.

[0024] Preferably, a third switch is connected in series between the output terminal of the voltage conversion circuit and the first terminal, and a fourth switch is connected in series between the output terminal of the power supply circuit and the third terminal.

[0025] The beneficial effects of this utility model are as follows: The relay detection circuit of this utility model, by setting a power supply circuit and a voltage conversion circuit, can conveniently supply power to the relay coil and contacts; by setting four terminals, it can conveniently connect the relay under test to the relay detection circuit, allowing the relay detection circuit to match different package sizes of the relays under test; by setting a voltage transformer, a current transformer, a CPU controller, and a digital tube, the resistance of the relay coil can be calculated efficiently and accurately and displayed during relay testing; by setting a first light-emitting diode and a first grounding resistor, it is possible to intuitively determine whether the relay contacts are activated; therefore, using the relay detection circuit of this utility model can effectively improve the detection efficiency and accuracy when testing relays, and the relay detection circuit of this utility model can be adapted to relays of different package sizes.

[0026] Furthermore, since a sliding rheostat is provided in the voltage conversion circuit, the voltage at the output terminal of the voltage conversion circuit can be changed by adjusting the resistance value of the sliding rheostat, thereby ensuring that the circuit level can be properly matched with the relay coil voltage specification, so that the relay detection circuit of this utility model can be compatible with the specifications of relays under test of different voltage levels.

[0027] Furthermore, by grounding the output terminal of the DC / DC converter through the first filter capacitor C2, noise can be filtered out, making the output voltage of the DC / DC converter more stable, and thus making the output voltage of the voltage conversion circuit more stable.

[0028] Furthermore, by simultaneously setting a USB power supply port and an on-board battery pack in the power supply circuit, the detection circuit can perform relay detection normally when there is a compatible USB port level, and can also perform relay detection normally using the battery pack when there is no USB port power supply. By using two methods to power the relay detection circuit, the reliability of the relay detection circuit of this utility model is effectively improved.

[0029] Furthermore, by connecting the first diode in series between the second switch and the input terminal of the voltage conversion circuit, the unidirectional flow of current can be ensured. When the battery pack voltage is lower than the input terminal voltage of the voltage conversion circuit, the diode is in a reverse cutoff state, which can effectively prevent external current from flowing back into the battery pack and avoid the battery being reverse charged or damaged.

[0030] By placing a first transient suppression diode between the negative and positive terminals of the USB power supply port, and a second transient suppression diode between the negative terminal of the battery pack and the anode of the first diode, the energy of the spike pulse can be quickly discharged, protecting the downstream circuitry. Attached Figure Description

[0031] The above and other objects, features, and advantages of the present invention will become readily understood by reading the following detailed description of exemplary embodiments with reference to the accompanying drawings. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0032] Figure 1 This is a schematic diagram illustrating the structure of a relay detection circuit according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram illustrating the circuit principle of a relay detection circuit according to an embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0035] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0036] Example of a relay detection circuit:

[0037] like Figure 1 and Figure 2As shown, the relay detection circuit of this utility model includes:

[0038] The power supply circuit has its output terminal connected to the input terminal of the voltage conversion circuit to provide DC voltage to the voltage conversion circuit.

[0039] A voltage conversion circuit is used to convert the magnitude of the DC voltage output by the power supply circuit;

[0040] The coil detection circuit includes: a first terminal PROBE_4, connected to the output of the voltage conversion circuit and also used to connect the first end of the relay coil A; a second terminal PROBE_3, grounded and also used to connect the second end of the relay coil; a voltage transformer PT, used to collect the voltage across the relay coil, with its secondary side connected to the AD sampling port of the CPU controller U1; and a current transformer CT, used to collect the current passing through the relay coil, with its secondary side connected to the AD sampling port of the CPU controller through a sampling resistor.

[0041] The CPU controller has its I / O pins connected to the digital tube DS1. It is used to calculate the resistance of the relay coil based on the voltage across the relay coil and the current through the relay coil, and then display the value on the digital tube.

[0042] The contact detection circuit includes: a third terminal PROBE_1, which is connected to the output of the power supply circuit and is also used to connect one of the contacts of the relay contact pair B; and a fourth terminal PROBE_2, which is connected in series with the first light-emitting diode BAT_LED and the first grounding resistor R2 and then grounded, and is also used to connect the other contact of the relay contact pair.

[0043] In this embodiment, the first terminal, the second terminal, the third terminal, and the fourth terminal can all be probes.

[0044] The working process of the relay testing circuit of this utility model is as follows: First, connect the first and second terminals to the coil of the relay under test, and connect the third and fourth terminals to the contact pair of the relay under test. Turn on the power circuit, and the current output from the voltage conversion circuit will flow through the coil of the relay under test. If the first LED changes from off to on when the contact pair is normally open, it indicates that the contact pair of the relay under test is normal. If the first LED changes from on to off when the contact pair is normally closed, it indicates that the contact pair of the relay under test is normal. Turn on the voltage conversion circuit, and the voltage transformer collects the voltage across the relay coil in real time. The current transformer collects the current flowing through the relay coil in real time. The CPU controller calculates the resistance value of the relay coil under test in real time based on the collected current and voltage, and displays it on the digital tube. The relay coil can be judged as normal based on the resistance value (if the resistance value is within the normal resistance range of the product, it indicates that the relay coil is qualified). Once the coil contacts and coil resistance of the relay under test are normal, the next product test can begin, and the relay that passes the test can be soldered into the product.

[0045] This invention relates to a relay detection circuit. By incorporating a power supply circuit and a voltage conversion circuit, it can conveniently power the relay coil and contacts. The four terminals allow for easy connection between the relay under test and the detection circuit, enabling the circuit to be compatible with relays of different package sizes. The inclusion of a voltage transformer, current transformer, CPU controller, and digital display allows for efficient and accurate calculation and display of the relay coil resistance during detection. The presence of a first LED and a first grounding resistor provides a direct visual indication of whether the relay contacts are activated. Therefore, this invention effectively improves the efficiency and accuracy of relay testing and is compatible with relays of different package sizes.

[0046] like Figure 2 As shown, in one embodiment, the voltage conversion circuit includes a DC / DC converter U2, whose input terminal V1+ is connected to the output terminal of the power supply circuit, and whose output terminal V2+ is connected to the first fixed terminal and the sliding terminal of the sliding rheostat CR, respectively. The second fixed terminal of the sliding rheostat is the output terminal of the voltage conversion circuit.

[0047] Different specifications of relays have different rated operating voltages. Because a sliding rheostat is included in the voltage conversion circuit, the voltage at the output of the voltage conversion circuit can be changed by adjusting the resistance value of the rheostat. This ensures that the circuit level can properly match the relay coil voltage specification, making the relay detection circuit of this invention compatible with relays of different voltage levels.

[0048] In this embodiment, the voltage conversion circuit can output three DC voltages—5V, 12V, and 24V—to power the relay coil by adjusting the resistance value of the sliding rheostat. In other embodiments, other levels of DC voltage can also be output.

[0049] To detect whether the DC / DC converter is usable, in one embodiment, the output terminal of the DC / DC converter is connected in series with a second grounding resistor R1 and a second light-emitting diode POWER_LED and then grounded.

[0050] When the voltage conversion circuit is available, the output of DC / DC converter U1 is at a high voltage, which drives the second LED after passing through the second grounding resistor. If the second LED lights up normally, it means that the DC / DC converter is available; otherwise, the DC / DC converter needs to be replaced.

[0051] In one embodiment, the output of the DC / DC converter is grounded through a first filter capacitor C2.

[0052] By grounding the output terminal of the DC / DC converter through the first filter capacitor C2, noise can be filtered out, making the output voltage of the DC / DC converter more stable, and thus making the output voltage of the voltage conversion circuit more stable.

[0053] In order to provide overvoltage protection for the load circuit of the DC / DC converter and suppress voltage spikes, in one embodiment, the output of the DC / DC converter is grounded through a Zener diode D2.

[0054] In one embodiment, the power supply circuit includes a USB power supply port U3 and a battery pack BT1. The positive terminal of the USB power supply port is connected to the first terminal of the first switch S1, the second terminal of the first switch S1 is connected to the input terminal of the voltage conversion circuit, and the positive terminal of the battery pack is connected to the input terminal of the voltage conversion circuit through the second switch S2.

[0055] In this embodiment, the rated voltage of the positive terminal of the battery pack is 6V. The positive voltage of the USB power supply port is 5V.

[0056] By controlling the on / off state of the first switch, the connection between the positive terminal of the USB power port and the subsequent circuit can be easily connected or disconnected. By controlling the on / off state of the second switch, the connection between the positive terminal of the battery pack and the subsequent circuit can be easily connected or disconnected.

[0057] By simultaneously incorporating a USB power supply port and an on-board battery pack into the power supply circuit, the detection circuit can perform relay detection normally when a compatible USB port level is available. When there is no USB port power supply, the battery pack can also be used to perform relay detection normally, thereby improving the reliability of the relay detection circuit of this invention.

[0058] In one embodiment, a first diode D1 is connected in series between the second switch and the input terminal of the voltage conversion circuit, wherein the anode of the first diode is connected to the second switch and the cathode is connected to the input terminal of the voltage conversion circuit.

[0059] By connecting the first diode in series between the second switch and the input terminal of the voltage conversion circuit, the unidirectional flow of current can be ensured. When the battery pack voltage is lower than the input voltage of the voltage conversion circuit, the diode is in a reverse cutoff state, which can effectively prevent external current from flowing back into the battery pack and avoid the battery being reverse charged or damaged.

[0060] In one embodiment, the negative terminal of the USB power supply port is connected to the first terminal of the first transient suppression diode TVS1, the second terminal of the first transient suppression diode is connected to the second terminal of the first switch, and grounded through the second filter capacitor C1; the negative terminal of the battery pack is grounded and connected to the anode of the first diode D1 through the second transient suppression diode TVS2.

[0061] By placing a first transient suppression diode between the negative and positive terminals of the USB power port, peak pulse energy can be quickly discharged, protecting subsequent circuitry. Similarly, by placing a second transient suppression diode between the negative terminal of the battery pack and the anode of the first diode, peak pulse energy can be quickly discharged, protecting subsequent circuitry.

[0062] In one embodiment, the anode of the first diode is connected to the fourth terminal via a push-button switch KEY1.

[0063] By connecting the anode of the first diode to the fourth terminal via a push-button switch, the push-button switch, the first LED, and the first grounding resistor form a battery pack detection circuit. When the push-button switch KEY1 is pressed, the first LED BAT_LED is driven through the current-limiting resistor R2. If the first LED BAT_LED lights up normally, it indicates that the battery pack is usable; otherwise, it indicates that the battery pack is unusable. This allows for a direct understanding of the battery pack's voltage level. If the battery pack is unusable, it needs to be replaced when testing the relay.

[0064] In one embodiment, a third switch S3 is connected in series between the output terminal of the voltage conversion circuit and the first terminal, and a fourth switch S4 is connected in series between the output terminal of the power supply circuit and the third terminal.

[0065] By setting a third switch, the output terminal of the voltage conversion circuit and the first terminal can be easily connected or disconnected; by setting a fourth switch, the output terminal of the power supply circuit and the third terminal can be easily connected or disconnected, thereby improving the safety of the relay detection circuit of this utility model.

[0066] While this specification has shown and described various embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the present invention. It should be understood that various alternatives to the embodiments of the present invention described herein may be employed in the practice of the present invention.

Claims

1. A relay detection circuit, characterized in that, include: The power supply circuit has its output terminal connected to the input terminal of the voltage conversion circuit to provide DC voltage to the voltage conversion circuit. A voltage conversion circuit is used to convert the magnitude of the DC voltage output by the power supply circuit; The coil detection circuit includes: a first terminal block connected to the output of a voltage conversion circuit and also used to connect the first end of a relay coil; a second terminal block grounded and also used to connect the second end of a relay coil; a voltage transformer for acquiring the voltage across the relay coil, with its secondary side connected to the AD sampling port of the CPU controller; a current transformer for acquiring the current flowing through the relay coil, with its secondary side connected to the AD sampling port of the CPU controller via a sampling resistor; and a CPU controller whose I / O pins are connected to a digital display for calculating the resistance of the relay coil based on the voltage across the relay coil and the current flowing through the relay coil, and displaying the value on the digital display. The contact detection circuit includes: a third terminal block, which is connected to the output of the power supply circuit and is also used to connect one of the contacts of the relay contact pair; and a fourth terminal block, which is connected to the ground in series with the first light-emitting diode and the first grounding resistor, and is also used to connect the other contact of the relay contact pair.

2. The relay detection circuit as described in claim 1, characterized in that, The voltage conversion circuit includes a DC / DC converter, whose input terminal is connected to the output terminal of the power supply circuit, and whose output terminal is connected to the first fixed terminal and the sliding terminal of the sliding rheostat, respectively. The second fixed terminal of the sliding rheostat is the output terminal of the voltage conversion circuit.

3. The relay detection circuit as described in claim 2, characterized in that, The output terminal of the DC / DC converter is connected to a second grounding resistor and a second light-emitting diode in series before being grounded.

4. The relay detection circuit as described in claim 2, characterized in that, The output of the DC / DC converter is grounded through a first filter capacitor.

5. The relay detection circuit as described in claim 2, characterized in that, The output of the DC / DC converter is grounded through a Zener diode.

6. The relay detection circuit as described in claim 1, characterized in that, The power supply circuit includes a USB power supply port and a battery pack. The positive terminal of the USB power supply port is connected to the first terminal of the first switch, and the second terminal of the first switch is connected to the input terminal of the voltage conversion circuit. The positive terminal of the battery pack is connected to the input terminal of the voltage conversion circuit through the second switch.

7. The relay detection circuit as described in claim 6, characterized in that, A first diode is connected in series between the second switch and the input terminal of the voltage conversion circuit, wherein the anode of the first diode is connected to the second switch and the cathode is connected to the input terminal of the voltage conversion circuit.

8. The relay detection circuit as described in claim 6, characterized in that, The negative terminal of the USB power supply port is connected to the first terminal of the first transient suppression diode, the second terminal of the first transient suppression diode is connected to the second terminal of the first switch, and grounded through the second filter capacitor; the negative terminal of the battery pack is grounded and connected to the anode of the first diode through the second transient suppression diode.

9. The relay detection circuit as described in claim 6, characterized in that, The anode of the first diode is connected to the fourth terminal via a push-button switch.

10. The relay detection circuit according to any one of claims 1 to 9, characterized in that, A third switch is connected in series between the output of the voltage conversion circuit and the first terminal, and a fourth switch is connected in series between the output of the power supply circuit and the third terminal.

Images