Power supply circuit, control circuit for heating device and heating device

Abstract

The invention provides a power supply circuit, which comprises a rectification circuit, a first filtering circuit, a boost-buck circuit and a controller, wherein the input end of the rectification circuit is connected to an alternating current power source to receive alternating current output by the alternating current power source and carry out rectification processing on the alternating current to obtain first direct current; the input end of the first filtering circuit is connected to the output end of the rectification circuit to carry out filtering processing on the first direct current so as to obtain second direct current; the input end of the boost-buck circuit is connected to the output end of the first filtering circuit to regulate the second direct current according to a received control signal so as to obtain third direct current, the first output end of the boost-buck circuit outputs the second direct current, and the second output end outputs third direct current; and the controller is connected to the boost-buck circuit to send a control signal to the boost-buck circuit. Correspondingly, the invention also provides a control circuit for a heating device and a heating device. According to the technical scheme, the output voltage of the power supply circuit can be regulated at will to satisfy different voltage requirements of users and provide the stable voltage for the users.

Description

technical field [0001] The invention relates to the technical field of heating, in particular to a power supply circuit, a control circuit of a heating device and a heating device. Background technique [0002] The existing induction cooker heating schemes mainly include single-tube, half-bridge and full-bridge circuit schemes, among which the block diagram and circuit structure of the main circuit of the induction cooker for the single-tube scheme are as follows: figure 1 and figure 2 As shown, it generally includes an anti-interference circuit 102 , a rectifier circuit 104 , a filter circuit 106 , an LC resonant circuit 108 , and a transistor control circuit 110 . The block diagram and circuit structure of the main circuit of the induction cooker in the half-bridge scheme are as follows: image 3 and Figure 4 As shown, it generally includes an anti-interference circuit 302 , a rectifier circuit 304 , a filter circuit 306 , an LC resonant circuit 308 , and a half-bridg...

AI Technical Summary

Problems solved by technology

The biggest feature of these three circuits is that the voltage of the main power circuit is determined by the input AC power supply voltage. Once the AC input voltage is fixed, the output voltage of the rectifier circuit cannot be adjusted. The induction cooker can only adjust the frequency and duty cycle of the heating transistor. Get different power (firepower); and when the AC voltage fluctuates, the rectified output voltage also fluctuates, which leads to the instability of the subsequent heating control circuit. When the AC input is too high, the transistor heated by a single tube may be overvoltage Impact may cause damage; while half-bridge and full-bridge induction cookers heat aluminum and copper pans due to high resonant frequency, the current peak value of the transistor is also high, voltage fluctuations are likely to cause the transistor current to exceed the range and overheat damage ; If the input voltage is very high, the high-frequency pulse current flowing through the transistor when the copper and aluminum pans are inspected is also very large, and the life of the device will decrease if it works for a long time

Since the output voltage cannot be adjusted after the AC voltage is rectified, it is also difficult for the induction cooker to achieve continuous low-power or high-power heating

Images