Low voltage power supply circuit of Joyoung JYC-22F induction cooker

Low voltage power supply circuit of Joyoung JYC-22F induction cooker

Shown is the low-voltage power supply circuit of Joyoung JYC-22F induction cooker .     AC 220 V voltage is applied to the primary of low-voltage power supply transformer Tl. Its secondary has two windings A and B. There is a tap in the middle of winding B, so that it has three terminals ①, ②, and ③. The two terminals ① and ⑧ convert AC into DC through a bridge rectifier circuit, and output 20 V DC voltage. The 2() V DC voltage is divided into two channels at point M, and one channel is sent to the electric fan through pin ① of plug CON2. As long as pin ② of CON2 is grounded, the electric fan can rotate. ②The grounding or disconnection of the pin is controlled by the microprocessor. The microprocessor adds a high level to the base of transistor VI2, and transistor VT2 is turned on. Current flows through the electric fan, and the electric fan can rotate.     The other branch from point M is a voltage stabilizing circuit. The base of transistor VT6 is equipped with a voltage stabilizing diode ZD5. After voltage stabilization, the emitter of transistor VT6 outputs a voltage of +20V. The +20V voltage then passes through the voltage stabilizing circuit composed of the transistor VT5 and the voltage stabilizing diode ZD1, and a DC voltage of +5 V can be output.