Low-voltage direct-current induction cooker control circuit

Abstract

The utility model provides a low-voltage direct-current induction cooker control circuit, which relates to the technical field of induction cooker control circuits and comprises a bridge rectifier circuit, an LC oscillating circuit, an IGBT (insulated gate bipolar transistor) power control circuit, a PWM (pulse-width modulation) circuit, an overcurrent and overvoltage detection circuit, a temperature detection circuit, a display module and an input key. The LC oscillating circuit is composed of an inductor and a capacitor. The utility model has the advantages that the output voltage in the control circuit is high, the ripple voltage is small, the power transformer is fully utilized, the efficiency is high, oscillation can be generated in the capacitor in the circuit, the accurate switching operation is realized through reasonable time sequence control, and the control circuit is suitable for large-scale popularization and application because the current is supplied to the load in the positive and negative half cycles of the power transformer. Therefore, high-efficiency power conversion is realized, and voltage and current in the circuit can be controlled by changing the time proportion of the high level and the low level of the PWM signal.

Description

Technical Field

[0001] This utility model relates to the field of induction cooker control circuit technology, and in particular to a low-voltage DC induction cooker control circuit. Background Technology

[0002] An induction cooker works on the principle of eddy current induction. A high-frequency current passing through a loop coil generates numerous enclosed magnetic fields, causing the pot itself to heat up rapidly, thus heating the food inside. When a high-frequency current passes through the coil, a high-frequency alternating magnetic field is generated around it. The magnetic lines of force generated in this alternating magnetic field pass through the bottom of a magnetically conductive material (such as an iron pot), causing numerous small eddy currents to form on the bottom of the pot. This results in the rapid release of a large amount of heat from the bottom of the pot, achieving the heating purpose.

[0003] However, existing induction cooker control circuits are not convenient for precise control of the time sequence during use, have low working efficiency, and are not convenient for controlling the voltage and current in the circuit. Utility Model Content

[0004] Therefore, the purpose of this utility model is to propose a low-voltage DC induction cooker control circuit to solve the problems mentioned in the background art and overcome the shortcomings of the existing technology.

[0005] To achieve the above objectives, one embodiment of this utility model provides a low-voltage DC induction cooker control circuit, including a bridge rectifier circuit, an LC oscillation circuit, an IGBT power control circuit, a PWM circuit, an overcurrent and overvoltage detection circuit, a temperature detection circuit, a display module, and input buttons. The bridge rectifier circuit is electrically connected to the LC oscillation circuit, the LC oscillation circuit is electrically connected to the IGBT power control circuit, and the IGBT power control circuit is electrically connected to the PWM circuit. The bridge rectifier circuit, LC oscillation circuit, IGBT power control circuit, and PWM circuit are all electrically connected to the overcurrent and overvoltage detection circuit and the temperature detection circuit. The circuit and temperature detection circuit are connected to the display module. The input buttons are electrically connected to the bridge rectifier circuit, LC oscillation circuit, IGBT power control circuit and PWM circuit. Inside the induction cooker, the rectifier circuit converts the 50Hz 220V AC voltage into a pulsating DC voltage. After being filtered by a capacitor, the DC voltage is converted into a high-frequency voltage with a frequency of 20KHz to 40KHz by the control circuit. The rapidly changing current flowing through the coil generates a rapidly changing magnetic field. When the magnetic lines of force in the magnetic field pass through the metal body at the bottom of the metal vessel (a magnetic and conductive material), a large number of strong eddy currents are generated. When the eddy currents are hindered by the resistance of the material, a large amount of heat is generated, thereby heating the food.

[0006] Preferably, the bridge rectifier circuit is mainly composed of a rectifier bridge. The working principle of the bridge rectifier is based on the unidirectional conduction characteristic of diodes to rectify AC power and convert it into DC power. The bridge rectifier consists of four rectifier diodes, usually connected in a bridge configuration, hence the name bridge rectifier. During the positive half-cycle of AC power, diodes D1 and D3 are forward biased and conduct, while D2 and D4 are reverse biased and cut off. In this way, the current can reach the load through D1 and D3. During the negative half-cycle, diodes D2 and D4 conduct, while D1 and D3 are cut off. Similarly, the current reaches the load through D2 and D4. The bridge rectifier circuit can generate a positive voltage drop in both the positive and negative half-cycles, thereby realizing the function of converting AC power into DC power. The advantages of this circuit are high output voltage and low ripple voltage. At the same time, since the power transformer supplies current to the load in both the positive and negative half-cycles, the power transformer is fully utilized and has high efficiency.

[0007] Preferably, the LC oscillation circuit is composed mainly of an inductor and a capacitor. The principle is based on the interaction between the capacitor and the inductor. When the capacitor and the inductor form a circuit, they will convert the electrical energy stored in each other to generate oscillation. Specifically, when the capacitor stores charge, the inductor receives magnetic field energy. When the capacitor discharges, the magnetic field energy in the inductor is converted into current and recharges the capacitor. This process is repeated to generate oscillation.

[0008] Preferably, in any of the above schemes, the basic principle of the IGBT control circuit is to control the voltage and current signals to realize the switching operation of the IGBT module. The drive circuit provides sufficient voltage and current to the gate of the IGBT through appropriate signal adjustment and amplification, so that it can be turned on or off in a controllable manner. Through reasonable time sequence control, precise switching operation is achieved, thereby realizing high-efficiency power conversion.

[0009] Preferably, in any of the above schemes, the basic principle of the PWM circuit is to control the voltage and current in the circuit by changing the pulse width. In the PWM signal, the high level lasts for a longer duration and the low level lasts for a shorter duration, thereby changing the power output in the circuit. Specifically, when the PWM signal is high, the switch in the circuit will open and the current will flow through the load; when the PWM signal is low, the switch will close and the current will stop flowing. Therefore, by changing the ratio of the high and low level times of the PWM signal, the voltage and current in the circuit can be controlled.

[0010] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows:

[0011] 1. The control circuit has a high output voltage and a small ripple voltage. At the same time, since the power transformer supplies current to the load during both the positive and negative half-cycles, the power transformer is fully utilized and has high efficiency. It can generate oscillation inside the capacitor in the circuit. Through reasonable time sequence control, precise switching operation can be achieved, thereby realizing high-efficiency power conversion. At the same time, by changing the ratio of the high and low level times of the PWM signal, the voltage and current in the circuit can be controlled.

[0012] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0013] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0014] Figure 1 This is a circuit layout diagram according to an embodiment of the present utility model;

[0015] Figure 2 This is a main control circuit diagram according to an embodiment of the present utility model. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0017] like Figure 1-2 As shown in the figure, a low-voltage DC induction cooker control circuit according to an embodiment of the present invention includes a bridge rectifier circuit, an LC oscillation circuit, an IGBT power control circuit, a PWM circuit, an overcurrent and overvoltage detection circuit, a temperature detection circuit, a display module, and input buttons. The bridge rectifier circuit is electrically connected to the LC oscillation circuit, the LC oscillation circuit is electrically connected to the IGBT power control circuit, and the IGBT power control circuit is electrically connected to the PWM circuit. The bridge rectifier circuit, the LC oscillation circuit, the IGBT power control circuit, and the PWM circuit are all electrically connected to the overcurrent and overvoltage detection circuit and the temperature detection circuit. The circuit signal is connected to the display module. The input buttons are electrically connected to the bridge rectifier circuit, LC oscillation circuit, IGBT power control circuit and PWM circuit. Inside the induction cooker, the rectifier circuit converts the 50Hz 220V AC voltage into a pulsating DC voltage. After being filtered by a capacitor, the DC voltage is converted into a high-frequency voltage with a frequency of 20KHz to 40KHz by the control circuit. The rapidly changing current flowing through the coil generates a rapidly changing magnetic field. When the magnetic lines of force in the magnetic field pass through the metal body at the bottom of the metal vessel (a magnetic and conductive material), a large number of strong eddy currents are generated. When the eddy currents are hindered by the resistance of the material, a large amount of heat is generated, thereby heating the food.

[0018] Preferably, the bridge rectifier circuit is mainly composed of a rectifier bridge. The working principle of the bridge rectifier is based on the unidirectional conduction characteristic of diodes to rectify AC power and convert it into DC power. The bridge rectifier consists of four rectifier diodes, usually connected in a bridge configuration, hence the name bridge rectifier. During the positive half-cycle of AC power, diodes D1 and D3 are forward biased and conduct, while D2 and D4 are reverse biased and cut off. In this way, the current can reach the load through D1 and D3. During the negative half-cycle, diodes D2 and D4 conduct, while D1 and D3 are cut off. Similarly, the current reaches the load through D2 and D4. The bridge rectifier circuit can generate a positive voltage drop in both the positive and negative half-cycles, thereby realizing the function of converting AC power into DC power. The advantages of this circuit are high output voltage and low ripple voltage. At the same time, since the power transformer supplies current to the load in both the positive and negative half-cycles, the power transformer is fully utilized and has high efficiency.

[0019] Preferably, the LC oscillation circuit is composed mainly of an inductor and a capacitor. The principle is based on the interaction between the capacitor and the inductor. When the capacitor and the inductor form a circuit, they will convert the electrical energy stored in each other to generate oscillation. Specifically, when the capacitor stores charge, the inductor receives magnetic field energy. When the capacitor discharges, the magnetic field energy in the inductor is converted into current and recharges the capacitor. This process is repeated to generate oscillation.

[0020] Preferably, in any of the above schemes, the basic principle of the IGBT control circuit is to control the voltage and current signals to realize the switching operation of the IGBT module. The drive circuit provides sufficient voltage and current to the gate of the IGBT through appropriate signal adjustment and amplification, so that it can be turned on or off in a controllable manner. Through reasonable time sequence control, precise switching operation is achieved, thereby realizing high-efficiency power conversion.

[0021] Preferably, in any of the above schemes, the basic principle of the PWM circuit is to control the voltage and current in the circuit by changing the pulse width. In the PWM signal, the high level lasts for a longer duration and the low level lasts for a shorter duration, thereby changing the power output in the circuit. Specifically, when the PWM signal is high, the switch in the circuit will open and the current will flow through the load; when the PWM signal is low, the switch will close and the current will stop flowing. Therefore, by changing the ratio of the high and low level times of the PWM signal, the voltage and current in the circuit can be controlled.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The control circuit has a high output voltage and a small ripple voltage. At the same time, since the power transformer supplies current to the load during both the positive and negative half-cycles, the power transformer is fully utilized and has high efficiency. It can generate oscillation inside the capacitor in the circuit. Through reasonable time sequence control, precise switching operation can be achieved, thereby realizing high-efficiency power conversion. At the same time, by changing the ratio of the high and low level times of the PWM signal, the voltage and current in the circuit can be controlled.

Claims

1. A control circuit for a low-voltage DC induction cooker, characterized in that: The system includes a bridge rectifier circuit, an LC oscillation circuit, an IGBT power control circuit, a PWM circuit, an overcurrent and overvoltage detection circuit, a temperature detection circuit, a display module, and input buttons. The bridge rectifier circuit is composed of a rectifier bridge. The LC oscillation circuit consists of an inductor and a capacitor. The bridge rectifier circuit is electrically connected to the LC oscillation circuit. The LC oscillation circuit is electrically connected to the IGBT power control circuit. The IGBT power control circuit is electrically connected to the PWM circuit. The bridge rectifier circuit, LC oscillation circuit, IGBT power control circuit, and PWM circuit are all electrically connected to the overcurrent and overvoltage detection circuit and the temperature detection circuit. The overcurrent and overvoltage detection circuit and the temperature detection circuit are connected to the display module. The input buttons are electrically connected to the bridge rectifier circuit, LC oscillation circuit, IGBT power control circuit, and PWM circuit.

2. The low-voltage DC induction cooker control circuit as described in claim 1, characterized in that: The bridge rectifier circuit operates based on the unidirectional conduction characteristic of diodes to rectify alternating current (AC) and convert it into direct current (DC). Internally, the bridge rectifier circuit contains a bridge rectifier consisting of four rectifier diodes connected in a bridge configuration. During the positive half-cycle of the AC current, diodes D1 and D3 are forward biased and conduct, while D2 and D4 are reverse biased and cut off. Current flows through D1 and D3 to the load. During the negative half-cycle, diodes D2 and D4 conduct, while D1 and D3 are cut off. Similarly, current flows through D2 and D4 to the load. The bridge rectifier circuit generates a positive voltage drop during both the positive and negative half-cycles.

3. The low-voltage DC induction cooker control circuit as described in claim 2, characterized in that: When the capacitor and inductor inside the LC oscillation circuit form a loop, they will convert the electrical energy stored in each other, generating an oscillation phenomenon.

4. The low-voltage DC induction cooker control circuit as described in claim 3, characterized in that: The IGBT power control circuit achieves switching operation by controlling voltage and current signals.

5. The low-voltage DC induction cooker control circuit as described in claim 4, characterized in that: The PWM circuit controls the voltage and current in the circuit by changing the pulse width. In the PWM signal, the high level lasts for a longer duration and the low level lasts for a shorter duration, thereby changing the power output in the circuit.

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