Power supply protection device for high-frequency thermal resistance igniter
Through the operational amplifier filtering and integration circuit design, combined with diode and capacitor buffering, the malfunction of the power protection device of the high-frequency thermal resistance igniter is solved, and the stability and safety of the power protection device are achieved.
Patent Information
- Application Number
- CN202421565651.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-04
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-07-04
AI Technical Summary
The existing high-frequency thermal resistance igniter power protection device is prone to malfunction due to current fluctuations, resulting in the igniter being automatically turned off.
The op amp filtering and integration circuit design is adopted, combined with diode and capacitor buffering, to ensure that the voltage signal is stable and then trigger the relay to cut off the power supply to avoid malfunctions.
It effectively avoids the power protection device from malfunctioning due to current fluctuations, ensuring the normal and safe use of the ignitor.
Smart Images
Figure CN223206818U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an igniter protection device, in particular to a high-frequency thermal resistance igniter power supply protection device. Background Art
[0002] A high-frequency thermistor igniter is a device used to ignite a burning rod for outdoor cutting. Igniters are powered by batteries. To prevent battery damage from current overload, igniters are typically equipped with a power protection device. This device samples the power supply current through a sampling resistor. When the voltage across the sampling resistor exceeds the specified value, indicating an overload, a relay is triggered to automatically shut off the power. Existing power protection devices directly compare the voltage across the sampling resistor with a reference voltage. Because igniters are prone to current fluctuations at the moment of power-on, conventional power protection devices can malfunction, causing the igniter to automatically shut down. Utility Model Content
[0003] The technical problem to be solved by the utility model is to provide a high-frequency thermal resistance igniter power supply protection device, which can solve the deficiencies of the prior art and reduce the malfunction of the power supply protection device.
[0004] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.
[0005] A high-frequency thermistor igniter power supply protection device, wherein a sampling voltage input terminal is connected to a positive input terminal of a first operational amplifier through a first diode and a first resistor connected in series, the positive input terminal of the first operational amplifier is grounded through a first capacitor, the negative input terminal of the first operational amplifier is grounded through a second resistor, the negative input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through a third resistor, the output terminal of the first operational amplifier is connected to the negative input terminal of the second operational amplifier through a fourth resistor, the negative input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through a fifth resistor, the positive input terminal of the second operational amplifier is connected to a reference voltage terminal through a sixth resistor, the positive input terminal of the second operational amplifier is grounded through a seventh resistor, the output terminal of the second operational amplifier is connected to the negative input terminal of the third operational amplifier through an eighth resistor, the negative input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier through a second capacitor and a ninth resistor connected in parallel, the positive input terminal of the third operational amplifier is grounded through a tenth resistor, and the output terminal of the third operational amplifier is connected to a relay control coil through an eleventh resistor.
[0006] Preferably, the first diode and the first resistor are connected to the positive input terminal of the fourth op amp through a third capacitor and a twelfth resistor connected in series, the positive input terminal of the fourth op amp is grounded through a fourth capacitor, the reverse input terminal of the fourth op amp is grounded through a thirteenth resistor, the reverse input terminal of the fourth op amp is connected to the output terminal of the fourth op amp through a fifth capacitor, and the output terminal of the fourth op amp is connected to the output terminal of the third op amp through a fourteenth resistor.
[0007] Preferably, the first diode and the first resistor are connected in series to ground via a second diode and a sixth capacitor.
[0008] The beneficial effect of adopting the above technical solution is that the utility model can effectively prevent the sampling voltage from momentarily exceeding the reference voltage and causing the protection device to malfunction. At the same time, the protection device can also be activated in time when the sampling voltage fluctuates frequently, ensuring the normal and safe use of the igniter. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a structural diagram of a specific implementation method of the utility model. DETAILED DESCRIPTION
[0010] Reference Figure 1 In a specific embodiment of the present invention, the sampling voltage input terminal IN1 is connected to the positive input terminal of the first operational amplifier U1 through a first diode D1 and a first resistor R1 connected in series. The positive input terminal of the first operational amplifier U1 is grounded through a first capacitor C1. The negative input terminal of the first operational amplifier U1 is grounded through a second resistor R2. The negative input terminal of the first operational amplifier U1 is connected to the output terminal of the first operational amplifier U1 through a third resistor R3. The output terminal of the first operational amplifier U1 is connected to the negative input terminal of the second operational amplifier U2 through a fourth resistor R4. The negative input terminal of the second operational amplifier U2 is connected to the negative input terminal of the third operational amplifier U1 through a fifth resistor R5. The output end of the second operational amplifier U2, the positive input end of the second operational amplifier U2 is connected to the reference voltage terminal IN2 through the sixth resistor R6, the positive input end of the second operational amplifier U2 is grounded through the seventh resistor R7, the output end of the second operational amplifier U2 is connected to the reverse input end of the third operational amplifier U3 through the eighth resistor R8, the reverse input end of the third operational amplifier U3 is connected to the output end of the third operational amplifier U3 through the second capacitor C2 and the ninth resistor R9 connected in parallel, the positive input end of the third operational amplifier U3 is grounded through the tenth resistor R10, and the output end of the third operational amplifier U3 is connected to the relay control coil K through the eleventh resistor R11.
[0011] The protection device's sampling resistor is connected in series to the power supply circuit, making the current and voltage across the sampling resistor proportional. By sampling its voltage, the magnitude of the power supply current can be directly reflected. The first op amp U1 performs a low-pass filter on the sampled voltage to remove high-frequency interference. The filtered sampled voltage is then compared with a reference voltage at the second op amp U2. When the sampled voltage is greater than the reference voltage, the second op amp U2 outputs a negative signal. This negative signal then passes through the negative integral of the third op amp U3, gradually increasing its output. When the output voltage of the third op amp U3 is greater than or equal to the operating voltage of the relay control coil K, the relay actuates, disconnecting the power circuit.
[0012] Because the first op amp U1 performs low-pass filtering, the protection device will not operate if a pulse current interference occurs in the power supply, which poses a hidden danger. To solve this problem, we connected a forward integration device in parallel to the main circuit of the protection device, so that the relay can be triggered in time when a continuous pulse current occurs. The structure of the forward integration device is as follows: the first diode D1 and the first resistor R1 are connected to the positive input of the fourth op amp U4 through a third capacitor C3 and a twelfth resistor R12 connected in series. The positive input of the fourth op amp U4 is grounded through a fourth capacitor C4, the reverse input of the fourth op amp U4 is grounded through a thirteenth resistor R13, the reverse input of the fourth op amp U4 is connected to the output of the fourth op amp U4 through a fifth capacitor C5, and the output of the fourth op amp U4 is connected to the output of the third op amp U3 through a fourteenth resistor R14. Among them, the third capacitor C3 is used to cut off low-frequency signals to prevent the stable sampling signal when the power supply is working normally from triggering the fourth op amp U4.
[0013] A second diode D2 (a voltage-stabilizing diode) and a sixth capacitor C6 are connected in series between the first diode D1 and the first resistor R1 to ground. When a spike in the sampled voltage, exceeding the maximum voltage, occurs, the second diode D2 conducts, and the large-capacity sixth capacitor C6 effectively buffers the spike to prevent overvoltage in the protection device. (The first capacitor C1, with its smaller capacity, cannot effectively buffer the spike.) The sampled voltage signal, buffered by the current capacitor C6, safely enters the subsequent circuitry of the protection device, triggering a relay to disconnect the power supply while ensuring safe operation of the protection device.
[0014] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.
[0015] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.
Claims
1. A high-frequency thermal resistance igniter power supply protection device, characterized in that: The sampling voltage input terminal (IN1) is connected to the positive input terminal of the first operational amplifier (U1) through a first diode (D1) and a first resistor (R1) connected in series, the positive input terminal of the first operational amplifier (U1) is grounded through a first capacitor (C1), the negative input terminal of the first operational amplifier (U1) is grounded through a second resistor (R2), the negative input terminal of the first operational amplifier (U1) is connected to the output terminal of the first operational amplifier (U1) through a third resistor (R3), the output terminal of the first operational amplifier (U1) is connected to the negative input terminal of the second operational amplifier (U2) through a fourth resistor (R4), and the negative input terminal of the second operational amplifier (U2) is connected to the output terminal of the second operational amplifier (U2) through a fifth resistor (R5). The first operational amplifier (U2) is connected to the reference voltage terminal (IN2) through a sixth resistor (R6), the second operational amplifier (U2) is connected to the reference voltage terminal (IN2) through a sixth resistor (R6), the second operational amplifier (U2) is connected to the reference voltage terminal (IN2) through a seventh resistor (R7), the output terminal of the second operational amplifier (U2) is connected to the reverse input terminal of the third operational amplifier (U3) through an eighth resistor (R8), the reverse input terminal of the third operational amplifier (U3) is connected to the output terminal of the third operational amplifier (U3) through a second capacitor (C2) and a ninth resistor (R9) connected in parallel, the third operational amplifier (U3) is connected to the reference voltage terminal (IN2) through a tenth resistor (R10), and the output terminal of the third operational amplifier (U3) is connected to the relay control coil (K) through an eleventh resistor (R11).
2. The high-frequency thermal resistance igniter power supply protection device according to claim 1, characterized in that: The first diode (D1) and the first resistor (R1) are connected to the positive input terminal of the fourth operational amplifier (U4) via a third capacitor (C3) and a twelfth resistor (R12) connected in series; the positive input terminal of the fourth operational amplifier (U4) is grounded via a fourth capacitor (C4); the negative input terminal of the fourth operational amplifier (U4) is grounded via a thirteenth resistor (R13); the negative input terminal of the fourth operational amplifier (U4) is connected to the output terminal of the fourth operational amplifier (U4) via a fifth capacitor (C5); and the output terminal of the fourth operational amplifier (U4) is connected to the output terminal of the third operational amplifier (U3) via a fourteenth resistor (R14).
3. The high-frequency thermal resistance igniter power supply protection device according to claim 2, characterized in that: The first diode (D1) and the first resistor (R1) are connected to ground via a second diode (D2) and a sixth capacitor (C6) connected in series.