A residual voltage capture circuit for an electric mosquito swatter grid

Abstract

The application discloses a residual voltage capturing circuit of an electric mosquito swatter grid, which comprises a trigger timing circuit and a probe delay-on circuit, and the trigger timing circuit comprises a double button, a constant current delay circuit, an operational amplifier output circuit and a relay driving circuit, one-way contact of the double button is connected in parallel across a high-voltage starting button in the electric mosquito swatter, the constant current delay circuit comprises a constant current circuit and a delay circuit, the constant current circuit comprises a potentiometer, a first stabilizing diode and a first triode, the operational amplifier output circuit comprises an operational amplifier and a second stabilizing diode, the relay driving circuit comprises a driving triode, a coil of a relay and a freewheeling diode, and the probe delay-on circuit comprises a contact of the relay, and the contact of the relay is located between the electric mosquito swatter grid and a probe of an oscilloscope; the application guarantees that the time when the trigger timing circuit receives a trigger signal and the time when the electric mosquito swatter is disconnected from power supply are highly consistent through the double button mode, and a relay is used at an output end, so that the application is electrically isolated from the electric mosquito swatter circuit.

Description

Technical Field

[0001] This invention relates to the field of electric mosquito swatter circuit technology, and more particularly to an electric mosquito swatter grid residual voltage capture circuit. Background Technology

[0002] In the circuit of an electric mosquito swatter, refer to Figure 1 To effectively kill mosquitoes, the voltage of the secondary high-voltage grid often reaches 2000~3000V when the high-voltage start button is pressed. According to Clause 22.103 of the insect killer standard 4706.76-2008, in order to prevent users from being shocked when they touch the high-voltage grid after releasing the high-voltage start button, electric mosquito swatters must meet the requirement that "the grid voltage does not exceed 34V after 1 second of disconnection from the power supply".

[0003] The conventional testing method involves connecting a 100MΩ oscilloscope probe in parallel across the grid to record the voltage changes at both ends. However, due to the small capacitance and high voltage at the ends of the electric mosquito swatter grid, and especially since the discharge resistor connected in parallel across the ends of the electric mosquito swatter is usually greater than or equal to 10MΩ, the influence of the 100 MΩ oscilloscope probe on the discharge at both ends of the grid cannot be ignored. This results in significant data deviations in the commonly used testing method.

[0004] If the probe is switched on manually after 1 second, there are two problems:

[0005] 1. It is difficult to synchronize the start time of manual timing with the release time of the high-voltage start button in the electric mosquito swatter;

[0006] 2. After a 1-second timer, it is difficult to ensure that the probe is switched on accurately. Summary of the Invention

[0007] The purpose of this invention is to provide a residual voltage capture circuit for electric mosquito swatters.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A residual voltage capture circuit for an electric mosquito swatter grid, characterized in that it includes a trigger timing circuit and a probe delay-on circuit.

[0010] The trigger timing circuit includes a double-pole button, a constant current delay circuit, an operational amplifier output circuit, and a relay drive circuit. One contact of the double-pole button is connected in parallel to the two ends of the high-voltage start button in the electric mosquito swatter.

[0011] The constant current delay circuit includes a constant current circuit and a delay circuit. The constant current circuit includes a potentiometer, a first Zener diode, and a first transistor. The other contact of the dual-pole button is connected to the anode of the first Zener diode and the base of the first transistor, respectively. The emitter of the first transistor is connected to the potentiometer. The delay circuit includes a delay capacitor and a ready button. The collector of the first transistor is connected to the anode of the delay capacitor and the ready button.

[0012] The operational amplifier output circuit includes an operational amplifier and a second Zener diode. The collector of the first transistor is connected to the non-inverting input terminal of the operational amplifier, and the cathode of the second Zener diode is connected to the inverting input terminal of the operational amplifier.

[0013] The relay driving circuit includes a driving transistor, a relay coil, and a freewheeling diode. The output terminal of the operational amplifier is connected to the base of the driving transistor. The collector of the driving transistor is connected to one end of the relay and the anode of the freewheeling diode, respectively. The other end of the relay is connected to +12V.

[0014] The probe delay-on circuit includes relay contacts located between the electric mosquito swatter grid and the oscilloscope probe.

[0015] Furthermore, the constant current circuit also includes a fourth resistor and a fifth resistor, the other contact of the double button is connected to the fifth resistor, and the fourth resistor is connected in series with the potentiometer.

[0016] Furthermore, the operational amplifier output circuit also includes a sixth resistor, which is connected to the negative terminal of the second Zener diode.

[0017] Furthermore, the relay drive circuit also includes a seventh resistor, which is connected between the output terminal of the operational amplifier and the base of the driving transistor.

[0018] The unit circuit structure used in this invention is simple and efficient. In particular, in the trigger timing circuit, one of the two buttons is connected in parallel to the two ends of the high-voltage start button in the electric mosquito swatter to replace the high-voltage start button in the electric mosquito swatter. The two buttons ensure that the time when the trigger timing circuit receives the trigger signal and the time when the electric mosquito swatter is disconnected from the power supply are highly consistent.

[0019] The present invention uses a double button at the trigger end and a relay at the output end, which makes the entire design circuit electrically isolated from the original electric mosquito swatter circuit, and the working state of the original electric mosquito swatter circuit is completely preserved.

[0020] This invention uses a constant current method to charge the delay capacitor. The value of the constant current depends only on the specific parameters of the resistor and potentiometer and is not affected by voltage fluctuations of the 12V power supply, ensuring the applicability of the 1-second delay time to different 12V power supplies.

[0021] The circuit of this invention reduces testing errors compared to the original method of always connecting the probe to the circuit by accurately triggering timing and automatically turning on after a delay. Compared to the method of manual timing and manual turn-on, it reduces human error and saves manpower and material costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an existing electric mosquito swatter circuit.

[0023] Figure 2 This is a circuit diagram showing the combination of the present invention and the electric mosquito swatter circuit;

[0024] Figure 3 This is a circuit diagram of the trigger timing circuit of the present invention;

[0025] Figure 4 This is a schematic diagram of the probe delay-on circuit of the present invention.

[0026] Figure label:

[0027] 1. Trigger timing circuit; 2. Probe delay connection circuit.

[0028] S1 high-voltage start button, S2 double-pole button, RP potentiometer, EC delay capacitor.

[0029] ZD1 is the first Zener diode, and ZD2 is the second Zener diode.

[0030] Transistor Q1, driver transistor Q2, op-amp U1, relay KA

[0031] D5 freewheeling diode. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention discloses a residual voltage capture circuit for an electric mosquito swatter grid, such as... Figure 2As shown, it includes a trigger timing circuit 1 and a probe delay connection circuit 2. The trigger timing circuit 1 includes a double button S2, a constant current delay circuit, an operational amplifier output circuit, and a relay drive circuit. One contact of the double button S2 is connected in parallel to the two ends of the high-voltage start button S1 in the electric mosquito swatter.

[0034] like Figure 3 As shown, the constant current delay circuit includes a constant current circuit and a delay circuit. The constant current circuit includes a potentiometer RP, a first Zener diode ZD1, a first transistor Q1, a fourth resistor R4, and a fifth resistor R5. The other contact of the double-pole button S2 is connected to the anode of the first Zener diode ZD1 and the base of the first transistor Q1, respectively. The emitter of the first transistor Q1 is connected to the potentiometer RP. The delay circuit includes a delay capacitor EC and a ready button S3. The collector of the first transistor Q1 is connected to the anode of the delay capacitor EC and the ready button S3. The other contact of the double-pole button S2 is connected to the fifth resistor R5. The fourth resistor R4 and the potentiometer RP are connected in series.

[0035] The first transistor Q1 is an S9015 PNP transistor, the fourth resistor R4 is 510Ω, the maximum resistance of potentiometer RP is 50KΩ, the fifth resistor is 1KΩ, the first Zener diode ZD1 has a stable voltage of 3.9V, the delay capacitor EC has a withstand voltage of 50V and a capacitance of 22μF.

[0036] like Figure 3 As shown, when the double button S2 is pressed (for a period of time), the electric mosquito swatter circuit is activated, the base of the first transistor Q1 is clamped to a high level, the first transistor Q1 is cut off, and the constant current delay circuit does not work. At this time, press the preparation button S3 to initialize the voltage of the delay capacitor EC to 0V. The electric mosquito swatter circuit stops working the instant the double button S2 is released. At the same time, the base of the first transistor Q1 is no longer clamped to a high level, the first transistor Q1 is turned on, and the constant current circuit starts to work, charging the delay capacitor EC with a constant current.

[0037] The operational amplifier output circuit includes operational amplifier U1, a second Zener diode ZD2, and a sixth resistor R6. Operational amplifier U1 is an LM358. The inverting input of operational amplifier U1 is clamped to the Zener voltage of the second Zener diode ZD2, which has a stable voltage of 5.1V. The collector of the first transistor Q1 is connected to the non-inverting input of operational amplifier U1, and the cathode of the second Zener diode ZD2 is connected to the inverting input of operational amplifier U1. The sixth resistor R6 is connected to the cathode of the second Zener diode ZD2 as a current-limiting resistor, and its value is 2KΩ.

[0038] The relay drive circuit includes a driver transistor Q2, a relay KA, a freewheeling diode D5, and a seventh resistor R7. The driver transistor Q2 is an S9013. The output terminal of the operational amplifier U1 is connected to the base of the driver transistor Q2. The collector of the driver transistor Q2 is connected to one end of the coil of the relay KA and the positive terminal of the freewheeling diode D5. The other end of the coil of the relay KA is connected to +12V. The seventh resistor R7 is connected between the output terminal of the operational amplifier U1 and the base of the driver transistor Q2 as a current-limiting resistor. The seventh resistor R7 is 1KΩ.

[0039] like Figure 4 As shown, the probe delay circuit 2 includes the contacts of relay KA, which are located between the electric mosquito swatter grid and the oscilloscope probe.

[0040] In the trigger timing circuit 1 of this invention, the double-pole button S2 is a double-pole micro switch. One contact of the double-pole button S2 is connected in parallel to the two ends of the high-voltage start button S1 to replace... Figure 1 The high-voltage start button S1 in the existing electric mosquito swatter technology.

[0041] When the double button S2 is pressed, both contacts in the double button S2 are connected simultaneously. Since one of the contacts is connected in parallel with the high-voltage start button S1 in the electric mosquito swatter, that is, the two ends of the high-voltage start button S1 are short-circuited, the effect is equivalent to pressing the high-voltage start button S1. Therefore, one contact in the double button S2 can replace the high-voltage start button S1.

[0042] When the double button S2 is pressed and held for a period of time, and then the ready button S3 is pressed again, the voltage of the delay capacitor EC is initialized to 0V, that is, the non-inverting input of the op-amp U1 is 0V. At this time, the op-amp U1 outputs a low level to the relay drive circuit, the relay KA does not work, the contacts of the relay KA do not close, and the oscilloscope probe and the electric mosquito swatter grid are not connected. At the moment the double button S2 is released, the electric mosquito swatter circuit stops working, and at the same time the first transistor Q1 is turned on, and the constant current circuit starts to work, charging the delay capacitor EC with a constant current.

[0043] After a 1-second delay, the voltage across the delay capacitor EC exceeds the voltage regulation value of the second Zener diode ZD2, and the op-amp output jumps to a high level. This high level is sent to the relay drive circuit, the coil of relay KA is energized, the contacts of relay KA close, and the circuit between the oscilloscope probe and the electric mosquito swatter grid is connected.

[0044] In a constant current delay circuit, changing the resistance of potentiometer RP adjusts the constant current value. Changing the constant current value adjusts the charging speed of the delay capacitor EC, thus adjusting the final delay time. During initial circuit debugging, the resistance of potentiometer RP needs to be adjusted to achieve a final delay time of 1 second.

[0045] The operating voltage of the relay KA coil is 12V. The contacts of the relay KA are connected between the electric mosquito swatter grid and the oscilloscope probe. Since the voltage between the electric mosquito swatter grids is as high as about 3000V, a relay with a high breakdown voltage between the contacts needs to be selected. In this example, the breakdown voltage of the relay KA contacts is 6KV.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A residual voltage capture circuit for an electric mosquito swatter grid, characterized in that, Includes a trigger timing circuit and a probe delay-on circuit. The trigger timing circuit includes a double-pole button (S2), a constant current delay circuit, an operational amplifier output circuit, and a relay drive circuit. One contact of the double-pole button (S2) is connected in parallel to the two ends of the high-voltage start button (S1) in the electric mosquito swatter. The constant current delay circuit includes a constant current circuit and a delay circuit. The constant current circuit includes a potentiometer (RP), a first Zener diode (ZD1), and a first transistor (Q1). The other contact of the double-pole button (S2) is connected to the anode of the first Zener diode (ZD1) and the base of the first transistor (Q1), respectively. The emitter of the first transistor (Q1) is connected to the potentiometer (RP). The delay circuit includes a delay capacitor (EC) and a ready button (S3). The collector of the first transistor (Q1) is connected to the anode of the delay capacitor (EC) and the ready button (S3). The operational amplifier output circuit includes an operational amplifier (U1) and a second Zener diode (ZD2). The collector of the first transistor (Q1) is connected to the non-inverting input terminal of the operational amplifier (U1), and the cathode of the second Zener diode (ZD2) is connected to the inverting input terminal of the operational amplifier (U1). The relay driving circuit includes a driving transistor (Q2), a relay coil (KA), and a freewheeling diode (D5). The output terminal of the operational amplifier (U1) is connected to the base of the driving transistor (Q2). The collector of the driving transistor (Q2) is connected to one end of the relay (KA) and the positive terminal of the freewheeling diode (D5). The other end of the relay (KA) is connected to +12V. The probe delay-on circuit includes the contacts of a relay (KA), which are located between the electric mosquito swatter grid and the oscilloscope probe.

2. The residual voltage capture circuit of the electric mosquito swatter grid according to claim 1, characterized in that, The constant current circuit also includes a fourth resistor (R4) and a fifth resistor (R5). The other contact of the double push button (S2) is connected to the fifth resistor (R5). The fourth resistor (R4) and the potentiometer (RP) are connected in series.

3. The residual voltage capture circuit of the electric mosquito swatter grid according to claim 1, characterized in that, The operational amplifier output circuit also includes a sixth resistor (R6), which is connected to the negative terminal of the second Zener diode (ZD2).

4. The residual voltage capture circuit of the electric mosquito swatter grid according to claim 1, characterized in that, The relay drive circuit also includes a seventh resistor (R7), which is connected between the output of the operational amplifier (U1) and the base of the driving transistor (Q2).

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