A switching control circuit of a stove

Abstract

The utility model discloses a switch machine control circuit of stove relates to igniter, including processing chip, switch trigger unit, alternating current switch unit, alternating current switch unit includes relay control module, first relay, second relay and self -restoring fuse, the input of relay control module is connected with the output pin of processing chip, and the output of relay control module is connected with the coil one end of first relay, second relay simultaneously, and the coil other end of first relay, second relay is connected with direct current power supply supply end, the normally open first contact of first relay is connected with the fire line, and the second contact of first relay is connected with the fire line power supply terminal of stove inner load, the normally open first contact of second relay is connected with zero line, and the second contact of second relay is connected with one end of self -restoring fuse, the utility model discloses not only played the load protection effect to stove, and still has self -restoring function, greatly reduced maintenance cost.

Description

Technical Field

[0001] This utility model relates to an igniter, and more specifically, to a power on / off control circuit for a stove. Background Technology

[0002] Commercial stoves are cooking equipment designed specifically for commercial use, typically found in restaurants, hotels, canteens, coffee shops, and other food service establishments. These stoves are designed and function to meet the high-efficiency cooking needs of commercial operations. Common types of commercial stoves include gas stoves, electric stoves, and steam ovens. Due to their specific applications, commercial stoves are generally used in environments with high temperatures. Since the stove itself is a heat source, poor heat dissipation in the installation environment can easily lead to high internal loads. High temperatures can easily cause overload, increasing the stove's operating power. Currently, this is typically addressed by using fuses for protection. If the overload is severe, the fuse will melt, protecting the stove. However, this requires subsequent fuse replacement, increasing maintenance difficulty. Furthermore, if the fuse is not replaced promptly, the stove may become unusable, disrupting the cooking process. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a stove on / off control circuit that addresses the shortcomings of the prior art. This circuit solves the problem that in the prior art, the circuit automatically activates the protection function when the stove is overloaded, but the stove cannot be used after the load is normal and the corresponding components need to be replaced.

[0004] The present invention discloses a stove on / off control circuit, comprising a processing chip and a switch triggering unit and an AC switch unit connected to the processing chip; the AC switch unit includes a relay control module, a first relay, a second relay, and a resettable fuse; the input terminal of the relay control module is connected to an output pin of the processing chip, and the output terminal of the relay control module is simultaneously connected to one end of the coils of the first and second relays, the other end of the coils of the first and second relays being connected to a DC power supply terminal; the normally open first contact of the first relay is connected to the live wire, the second contact of the first relay is connected to the live wire power supply terminal of the load inside the stove, the normally open first contact of the second relay is connected to the neutral wire, the second contact of the second relay is connected to one end of the resettable fuse, and the other end of the resettable fuse is connected to the neutral wire power supply terminal of the load inside the stove.

[0005] Preferably, the tripping current of the self-resetting fuse is 2A to 4A.

[0006] Preferably, the tripping current of the self-resetting fuse is 3A.

[0007] Preferably, the relay control module includes a second resistor, a second transistor, a fifth diode, and a sixth diode; one end of the second resistor is connected to the output pin of the processing chip, the other end of the second resistor is connected to the base of the second transistor, the emitter of the second transistor is grounded, the collector of the second transistor is connected to one end of the coils of both the first and second relays, the two ends of the fifth diode are connected one-to-one with the two ends of the coil of the first relay, and the two ends of the sixth diode are connected one-to-one with the two ends of the coil of the second relay.

[0008] Preferably, the end of the second resistor connected to the processing chip is grounded through a seventh capacitor.

[0009] Preferably, the switch triggering unit includes a sixth resistor, a Hall sensor, an eighth resistor, and a second capacitor; one end of the sixth resistor is connected to the DC power supply terminal, the other end of the sixth resistor is connected to the signal input terminal of the Hall sensor, the signal output terminal of the Hall sensor is connected to the signal acquisition pin of the processing chip through the eighth resistor, and the signal output terminal of the Hall sensor is grounded through the second capacitor.

[0010] Preferably, the Hall sensor is model ST2103.

[0011] Preferably, the power on / off control circuit further includes a lighting unit.

[0012] Preferably, the lighting unit includes a third resistor, a third transistor, and a lighting module composed of a current-limiting resistor and a light-emitting diode; one end of the third resistor is connected to the other output terminal of the processing chip, and the connection terminal of the third resistor and the processing chip is grounded through an eighth capacitor; the other end of the third resistor is connected to the gate of the third transistor, and the emitter of the third transistor is grounded; one end of the current-limiting resistor serves as the input terminal of the lighting module and is connected to the DC power supply terminal; the other end of the current-limiting resistor is connected to the anode of the light-emitting diode; and the cathode of the light-emitting diode serves as the output terminal of the lighting module and is connected to the collector of the third transistor.

[0013] Preferably, four lighting modules are provided, and the four lighting modules are connected in parallel.

[0014] Beneficial effects

[0015] The advantages of this utility model are:

[0016] 1. This utility model incorporates a self-resetting fuse at the common contact of the second relay. The other end of the self-resetting fuse is connected to the neutral power supply terminal inside the stove. When the stove is overloaded, the self-resetting fuse will overheat and trip, disconnecting the 220VAC electrical equipment in the stove from the mains power and preventing it from operating. This ensures that the stove will not operate under overload conditions for extended periods, thus protecting the stove. Furthermore, the self-resetting fuse has a self-resetting function, allowing the stove to start and operate normally after returning to normal, significantly reducing maintenance costs.

[0017] 2. This utility model avoids the problem of contact switches being difficult to open due to oil contamination by using a magnetic induction Hall sensor as the start button element.

[0018] 3. This utility model uses relays to connect both the neutral and live wire input terminals of the 220VAC electrical equipment to the neutral and live wires of the mains power supply. This enables simultaneous switching on and off of the neutral and live wires, which is safer than the traditional single-wire disconnection circuit structure. Moreover, the two relays are controlled by the same relay control module, allowing their start and stop to be synchronized, resulting in better control performance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the power-on / off control circuit of this utility model. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, but this does not constitute any limitation on the present invention. Any limited modifications made by any person within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0021] See Figure 1 This utility model discloses a stove on / off control circuit, including a processing chip U2 and a switch triggering unit and an AC power switch unit connected to the processing chip U2. The processing chip U2 is a microcontroller, such as an 89 series microcontroller chip. The switch triggering unit is used to trigger the relay in the AC power switch unit to supply power to the stove's 220VAC electrical equipment. Specifically, the switch triggering unit includes a sixth resistor R6, a Hall sensor U1, an eighth resistor, and a second capacitor C2. In this embodiment, the Hall sensor U1 is model ST2103, but it is not limited to this model; other models of Hall sensors can be used as equivalent substitutes. One end of the sixth resistor R6 is connected to the DC power supply terminal, and the other end of the sixth resistor R6 is connected to the signal input terminal of the Hall sensor U1. The signal output terminal of the Hall sensor U1 is connected to the signal acquisition pin of the processing chip U2 through the eighth resistor R8, and the signal output terminal of the Hall sensor U1 is grounded through the second capacitor C2.

[0022] In many common commercial stoves, the start button typically uses a contact switch. However, due to the oily and fumes in the environment where commercial stoves are used, contact switches are prone to oil contamination and poor contact. Therefore, this embodiment uses a magnetically inductive Hall sensor U1 as the start button element, avoiding the problem of contact switches being difficult to open due to oil contamination. The specific installation method of the Hall sensor U1 and its switch triggering unit can be referenced from the existing installation methods of contact switches and their peripheral circuits. Those skilled in the art can easily implement the installation, and this invention does not improve upon it; therefore, the specific installation method will not be described. When the Hall sensor U1 is triggered, the initial level of the pin of the processing chip U2 connected to the signal output terminal of the Hall sensor U1 will change, i.e., the switch terminal in the Hall sensor U1 will conduct to ground, thus changing the pin from a high level to a low level. The sixth resistor R6 acts as a current-limiting resistor to prevent excessive current supply from the DC power supply terminal from damaging the Hall sensor U1; while the second capacitor C2 is used for filtering to improve the voltage stability of the signal output terminal of the Hall sensor U1.

[0023] The AC switching unit includes a relay control module, a first relay JDQ1A, a second relay JDQ2A, and a resettable fuse (PTC). The input terminal of the relay control module is connected to an output pin of the processing chip U2. The output terminal of the relay control module is simultaneously connected to one end of the coils of both the first relay JDQ1A and the second relay JDQ2A. The other ends of the coils of both relays are connected to the DC power supply terminal. The normally open first contact of the first relay JDQ1A is connected to the live wire, and the second contact of the first relay is connected to the live wire power supply terminal inside the stove. The normally open first contact of the second relay JDQ2A is connected to the neutral wire. The processing chip U2 can simultaneously control the operation of both relays through the relay control module. When power is needed for the 220VAC electrical equipment in the stove, the output pin of the processing chip U2 outputs a control signal to the relay control module, causing both relays to operate simultaneously. The normally open contacts connect to the common terminal, thereby connecting the 220VAC electrical equipment to the mains power supply. Furthermore, to address the issue in existing technologies where the circuit automatically activates its protection function due to stove overload, but the stove becomes unusable after the load returns to normal, requiring component replacement, this invention incorporates a resettable PTC fuse at the second contact of the second relay JDQ2A. The other end of the PTC fuse is connected to the neutral power supply terminal within the stove. Thus, when the stove is overloaded, the PTC fuse will overheat and disconnect, disconnecting the 220VAC electrical equipment within the stove from the mains power and preventing it from operating. Since the PTC fuse requires a certain amount of time to reset, and the stove will not restart immediately after the power supply is disconnected, it must wait for the PTC fuse to return to normal before the stove can be restarted. During this period, the load is effectively cooled and returns to its normal power level. For PTC self-resetting fuses with short recovery times, a label can be affixed to the stove or the stove's instruction manual can be provided with a reference time for the stove to remain stationary after self-protection. This prevents users from turning on the stove before the PTC self-resetting fuse has recovered but the load has not yet returned to normal power levels, thus preventing the stove from triggering a short-term second automatic protection.

[0024] For most commercial stoves, a tripping current of 2A to 4A is sufficient; too high or too low a current may affect the normal operation of the stove. In this embodiment, the tripping current of the PTC is specifically set to 3A, which meets the self-protection requirements of most stoves.

[0025] The relay control module includes a second resistor R2, a second transistor Q2, a fifth diode D5, and a sixth diode D6. One end of the second resistor R2 is connected to the output pin of the processing chip U2, and the other end is connected to the base of the second transistor Q2. The emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to one end of the coils of both the first relay JDQ1A and the second relay JDQ2A. The two ends of the fifth diode D5 are connected one-to-one with the two ends of the coil of the first relay JDQ1A, and the two ends of the sixth diode D6 are connected one-to-one with the two ends of the coil of the second relay JDQ2A. The end of the second resistor R2 connected to the processing chip U2 is grounded through a seventh capacitor C7. This circuit is a commonly used control circuit in relays, and therefore will not be discussed further.

[0026] In this embodiment, the power on / off control circuit also includes a lighting unit for illuminating the stove. That is, when the stove is started via the Hall sensor U1, the lighting unit also activates to illuminate the area, making it convenient for the user.

[0027] Specifically, the lighting unit includes a third resistor R3, a third transistor Q3, and a lighting module consisting of a current-limiting resistor and a light-emitting diode (LED). One end of the third resistor R3 is connected to the other output terminal of the processing chip U2, and the connection between the third resistor R3 and the processing chip U2 is grounded through the eighth capacitor C8. The other end of the third resistor R3 is connected to the gate of the third transistor Q3, and the emitter of the third transistor Q3 is grounded. One end of the current-limiting resistor serves as the input terminal of the lighting module and is connected to the DC power supply terminal. The other end of the current-limiting resistor is connected to the anode of the LED, and the cathode of the LED serves as the output terminal of the lighting module and is connected to the collector of the third transistor Q3. When the other output terminal of the processing chip U2 outputs a control signal, the third transistor Q3 conducts, thereby causing the LED to emit light and achieving lighting.

[0028] Preferably, there are four lighting modules connected in parallel, which can achieve better lighting effect. In addition, the arrangement of multiple light-emitting diodes is also conducive to the heat dissipation of the light-emitting diodes themselves and to the improvement of their service life.

[0029] In this embodiment, the DC power supply voltage is 12V, which can be powered by a battery or a power adapter. When using a power adapter, the input terminal of the power adapter is directly connected to the AC power supply.

[0030] The working principle of this invention is as follows: When the user presses the switch position on the stove where the Hall sensor U1 is installed, the Hall sensor U1 will activate, causing its pin connected to the processing chip U2 to ground, resulting in both this pin and the signal acquisition pin of the processing chip U2 being at a low level. At this time, after the level of the signal acquisition pin of the processing chip U2 changes, it will send a control signal to the relay control module, causing both relays to activate, thereby connecting the 22VAC electrical equipment in the stove to the mains power. Simultaneously, the processing chip U2 also generates another control signal to the lighting unit, causing the LEDs of the lighting unit to light up. When the stove is overloaded, the resettable fuse PTC will overheat and disconnect, thus disconnecting the 220VAC electrical equipment in the stove from the mains power and preventing it from working. Once the resettable fuse PTC returns to normal and / or the load returns to normal, the stove can be restarted through this control circuit.

[0031] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present utility model. These modifications and improvements will not affect the effectiveness of the present utility model or the practicality of the patent.

Claims

1. A switch-on / off control circuit for a stove, characterized in that, The system includes a processing chip (U2) and a switch triggering unit and an AC switch unit connected to the processing chip (U2). The AC switch unit includes a relay control module, a first relay (JDQ1A), a second relay (JDQ2A), and a resettable fuse (PTC). The input terminal of the relay control module is connected to an output pin of the processing chip (U2), and the output terminal of the relay control module is simultaneously connected to one end of the coil of both the first relay (JDQ1A) and the second relay (JDQ2A). The other end of the coil of the first relay (JDQ1A) and the second relay (JDQ2A) is connected to the DC power supply terminal; the normally open first contact of the first relay (JDQ1A) is connected to the live wire, the second contact of the first relay is connected to the live wire power supply terminal of the load inside the stove, the normally open first contact of the second relay (JDQ2A) is connected to the neutral wire, the second contact of the second relay (JDQ2A) is connected to one end of the resettable fuse (PTC), and the other end of the resettable fuse (PTC) is connected to the neutral wire power supply terminal of the load inside the stove.

2. The on / off control circuit for a stove according to claim 1, characterized in that, The tripping current of the resettable fuse (PTC) is 2A to 4A.

3. The on / off control circuit for a stove according to claim 2, characterized in that, The tripping current of the resettable fuse (PTC) is 3A.

4. The on / off control circuit for a stove according to claim 1, characterized in that, The relay control module includes a second resistor (R2), a second transistor (Q2), a fifth diode (D5), and a sixth diode (D6). One end of the second resistor (R2) is connected to the output pin of the processing chip (U2), and the other end of the second resistor (R2) is connected to the base of the second transistor (Q2). The emitter of the second transistor (Q2) is grounded, and the collector of the second transistor (Q2) is connected to one end of the coils of both the first relay (JDQ1A) and the second relay (JDQ2A). The two ends of the fifth diode (D5) are connected one-to-one with the two ends of the coil of the first relay (JDQ1A), and the two ends of the sixth diode (D6) are connected one-to-one with the two ends of the coil of the second relay (JDQ2A).

5. The on / off control circuit for a stove according to claim 4, characterized in that, The end of the second resistor (R2) connected to the processing chip (U2) is grounded through the seventh capacitor (C7).

6. The on / off control circuit for a stove according to claim 1, characterized in that, The switch triggering unit includes a sixth resistor (R6), a Hall sensor (U1), an eighth resistor, and a second capacitor (C2). One end of the sixth resistor (R6) is connected to the DC power supply terminal, and the other end of the sixth resistor (R6) is connected to the signal input terminal of the Hall sensor (U1). The signal output terminal of the Hall sensor (U1) is connected to the signal acquisition pin of the processing chip (U2) through the eighth resistor (R8), and the signal output terminal of the Hall sensor (U1) is grounded through the second capacitor (C2).

7. The on / off control circuit for a stove according to claim 1, characterized in that, The Hall sensor (U1) is model ST2103.

8. The on / off control circuit for a stove according to claim 1, characterized in that, The power on / off control circuit also includes a lighting unit.

9. The on / off control circuit for a stove according to claim 8, characterized in that, The lighting unit includes a third resistor (R3), a third transistor (Q3), and a lighting module consisting of a current-limiting resistor and a light-emitting diode (LED). One end of the third resistor (R3) is connected to the other output terminal of the processing chip (U2), and the connection between the third resistor (R3) and the processing chip (U2) is grounded through an eighth capacitor (C8). The other end of the third resistor (R3) is connected to the gate of the third transistor (Q3), and the emitter of the third transistor (Q3) is grounded. One end of the current-limiting resistor serves as the input terminal of the lighting module and is connected to the DC power supply terminal. The other end of the current-limiting resistor is connected to the anode of the LED, and the cathode of the LED serves as the output terminal of the lighting module and is connected to the collector of the third transistor (Q3).

10. The on / off control circuit for a stove according to claim 9, characterized in that, The lighting module is provided in four parts, and the four lighting modules are connected in parallel.

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