CN215300961U

CN215300961U - Low-power continuous heating circuit of induction cooker

Info

Publication number: CN215300961U
Application number: CN202121785335.0U
Authority: CN
Inventors: 黄宏
Original assignee: Guangdong Gelaru Energy Saving Technology Co ltd
Current assignee: Guangdong Gelaru Energy Saving Technology Co ltd
Priority date: 2021-07-31
Filing date: 2021-07-31
Publication date: 2021-12-24
Anticipated expiration: 2031-07-31

Abstract

A low-power continuous heating circuit of an induction cooker comprises input ends of input L and input N, an inductor L2, at least two resonant capacitors with different capacities, a single-pole double-throw switch, a main control module and an IGBT (insulated gate bipolar transistor) driving circuit; the input end of the inductor L2 is connected with the inductor L2, the inductor L2 is connected with the resonant capacitor, and the plurality of resonant capacitors are connected in parallel; the main control module is connected with the resonance capacitor and used for detecting the voltage of the resonance capacitor; the main control module is further connected with the single-pole double-throw switch, the single-pole double-throw switch is further connected with the resonant capacitor, and the resonant capacitor is further connected with the IGBT driving circuit and used for turning on the designated resonant capacitor to drive the IGBT driving circuit to work.

Description

Low-power continuous heating circuit of induction cooker

Technical Field

The utility model relates to an electromagnetism stove field especially relates to an electromagnetism stove low-power continuous heating circuit.

Background

The induction cooker is a new kitchen small household appliance, and is rapidly popularized due to the advantages of no open fire, high heat efficiency and the like. At present, a civil electromagnetic oven usually adopts a power tube (hereinafter referred to as a single tube for short), energy storage of an induction coil is realized by opening the power tube, and after the power tube (because the power tube of the electromagnetic oven is mostly an IGBT, and the later description mainly uses the IGBT) is closed, the induction coil and a resonant capacitor generate oscillation to generate high voltage on the induction coil. Due to the single-tube circuit structure, the wire coil is superposed with the oscillation of the resonant capacitor and the direct current after the commercial power rectification and filtration, when the power is high, the resonant voltage is high, the direct current component can be offset by the superposed result, and the IGBT can realize zero-crossing opening. When the power is lower, the resonance voltage is relatively reduced, and the direct-current voltage is difficult to counteract, so that the IGBT is hard to turn on, the loss is large, the heating is severe, and even the life of the IGBT is difficult to guarantee in severe cases. Therefore, the conventional single-tube circuit cannot realize low power of about 300W without circuit improvement.

In conclusion, a new and safe low-power continuous heating mode for a household boiler is an urgent problem to be solved.

SUMMERY OF THE UTILITY MODEL

The traditional low-power continuous heating scheme adopts a multi-stage resonant capacitor parallel connection mode, leakage inductance is increased due to the fact that a plurality of parallel capacitors are arranged at high power, the voltage-resistant characteristic of the capacitors can be reduced, and the working stability of a circuit is affected. In order to overcome the withstand voltage characteristic of the reduction electric capacity of current electromagnetism stove low-power continuous heating control circuit, poor stability not enough, the utility model provides an avoid reducing withstand voltage characteristic of electric capacity, improve job stabilization's electromagnetism stove low-power continuous heating control circuit.

In order to achieve the purpose, the technical scheme is as follows:

a low-power continuous heating circuit of an induction cooker comprises input ends of input L and input N, an inductor L2, at least two resonant capacitors with different capacities, a single-pole double-throw switch, a main control module and an IGBT (insulated gate bipolar transistor) driving circuit;

wherein the input terminal is connected with the inductor L2, the inductor L2 is connected with the resonant capacitor, and a plurality of resonant capacitors are connected in parallel;

the main control module is connected with the resonance capacitor and used for detecting the voltage of the resonance capacitor;

the main control module is further connected with the single-pole double-throw switch, the single-pole double-throw switch is further connected with the resonant capacitor, and the resonant capacitor is further connected with the IGBT driving circuit and used for switching on the designated resonant capacitor to drive the IGBT driving circuit to work.

In some embodiments, the single pole double throw switch comprises a relay, a transistor Q6, and a resistor;

a common contact of the relay is connected with the inductor L2, and a normally closed contact is connected with the resonance capacitor;

the positive pole of the relay inputs voltage, and the negative pole is grounded through the triode Q6;

and the base electrode of the triode Q6 is connected with the main control module through the resistor.

In some embodiments, three resonant capacitors are provided, namely a resonant capacitor C4, a resonant capacitor C5 and a resonant capacitor C6, the capacities of which are 5UF, 0.27UF and 0.27UF respectively, wherein the resonant capacitor C5 and the resonant capacitor C6 correspond to one single-pole double-throw switch respectively.

In some embodiments, a switching power supply circuit is further included, which includes a +18V voltage, a chip U3 connected to the +18V voltage for outputting a +5V voltage, a transformer T1A and a transformer T1B connected to the +18V voltage, a chip U1 connected to the transformer T1A, and a +300V voltage connected to the chip U1.

In some embodiments, the transistor Q6 is model SS 8050.

In some embodiments, the relay is model HF32 FV-16.

The application provides an avoid reducing the withstand voltage characteristic of electric capacity, improve job stabilization's electromagnetism stove low power continuous heating control circuit, can detect and realize the selection of different resonance electric capacity according to actual conditions, not only protect IGBT drive circuit, can also realize 300W's low power output.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below.

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to further explain the present invention in detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a low-power continuous heating circuit of an induction cooker includes input terminals for inputting L and N, an inductor L2, at least two resonant capacitors with different capacities, a single-pole double-throw switch, a main control module and an IGBT driving circuit, where the main control module is a chip U2;

As a preferred embodiment, the single-pole double-throw switch comprises a relay, a transistor Q6 and a resistor;

As a preferred embodiment, the resonant capacitors are three, namely a resonant capacitor C4, a resonant capacitor C5 and a resonant capacitor C6, the capacities of which are 5UF, 0.27UF and 0.27UF respectively, wherein the resonant capacitor C5 and the resonant capacitor C6 correspond to one single-pole double-throw switch respectively.

As a preferred embodiment, the power supply further comprises a switching power supply circuit, which comprises a +18V voltage, a chip U3 connected with the +18V voltage for outputting a +5V voltage, a transformer T1A and a transformer T1B connected with the +18V voltage, a chip U1 connected with the transformer T1A, and a +300V voltage connected with the chip U1.

In a preferred embodiment, the transistor Q6 is model SS 8050.

In a preferred embodiment, the relay is of the type HF32 FV-16.

The working principle of the application is as follows:

the input end outputs the live wire voltage to the IGBT driving circuit after resonance through an inductor L2 and a capacitor, when a chip U2 detects that one end of the inductor L2 is positive voltage through

pins

2 and 3 and signals C1N and C1P, the IGBT driving circuit can be operated, the voltage borne by the IGBT driving circuit is the voltage on the capacitor C1 minus the voltage on the inductor L2, namely VC4-VL2B, when VL2B is larger than VC4, the IGBT driving circuit is in a soft opening state, at the moment, the IGBT driving circuit is in an optimal resonance state, otherwise, the IGBT driving circuit is in a hard opening state, the IGBT driving circuit is rapidly heated and even damaged due to the hard opening state, at the time of low power, the detection feedback is carried out through the chip U2, and signals are output to a triode Q6, so that the positive electrode and negative electrodes of a relay are electrified, a common contact is communicated with a normally open contact, the common contact is switched to a small-capacity resonance capacitor, the small-capacity resonance capacitor is used for resonance, the amplitude of the LC is improved, and when the high-power is carried out, then switch to large capacity resonance electric capacity on, effectual reduction resonance voltage guarantees that IGBT drive circuit can work safely on big or miniwatt, therefore the utility model provides an avoid reducing the withstand voltage characteristic of electric capacity, improve job stabilization's electromagnetism stove low-power continuous heating control circuit.

The above description is only for the purpose of illustrating the preferred embodiments of the present application and is not intended to limit the scope of the present application, which is within the scope of the present application, except that the same or similar principles and basic structures as the present application may be used.

Claims

1. A low-power continuous heating circuit of an induction cooker is characterized in that: the circuit comprises input ends for inputting L and N, an inductor L2, at least two resonant capacitors with different capacities, a single-pole double-throw switch, a main control module and an IGBT drive circuit;

2. The low-power continuous heating circuit of the induction cooker according to claim 1, characterized in that: the single-pole double-throw switch comprises a relay, a triode Q6 and a resistor;

3. The low-power continuous heating circuit of the induction cooker according to claim 2, characterized in that: the three resonant capacitors are respectively a resonant capacitor C4, a resonant capacitor C5 and a resonant capacitor C6, the capacities of the three resonant capacitors are respectively 5UF, 0.27UF and 0.27UF, and the resonant capacitor C5 and the resonant capacitor C6 respectively correspond to one single-pole double-throw switch.

4. The low-power continuous heating circuit of the induction cooker according to claim 3, characterized in that: the power supply circuit also comprises a switching power supply circuit, wherein the switching power supply circuit comprises a +18V voltage, a chip U3 connected with the +18V voltage and used for outputting a +5V voltage, a transformer T1A and a transformer T1B connected with the +18V voltage, a chip U1 connected with the transformer T1A and a +300V voltage connected with the chip U1.

5. The low-power continuous heating circuit of the induction cooker according to claim 4, characterized in that: the model of the triode Q6 is SS 8050.

6. The low-power continuous heating circuit of the induction cooker according to claim 5, characterized in that: the relay is of the type HF32 FV-16.