330W AC regulated power supply circuit design

The 330W AC regulated power supply circuit is shown in the figure below. The working principle: R2, R4, R5, R6 The actual values ​​of the five sampling resistors should be: 470kΩ±3kΩ, 3.7kΩ±300Ω, 1.5kΩ±100Ω, 1.8kΩ±100Ω, 8.2kΩ±200Ω; light-emitting diode VD5: BT312 (red); VD15, VD17: BT313 (green); voltage-stabilizing diodes VD10, VD14: 2CW10 (1.5~2.5V), which can be replaced by three 3DG emitter junctions in series; transistor VT1: 9013, β=70; VT2, VT4, VT5: 9013, β≥100; VT3, VT6, VT7: 9013, β=100; VT8: 9012, β=100; VT9: 9012, β≥100; VT3, VT7, VT8 The penetration current of the three tubes should not be greater than 0.5μA; integrated circuits Al~A4: LM324; the leakage resistance of C9 capacitor measured with a pointer multimeter 1k block should be no less than 1.5MΩ; T1 uses an ordinary 36V±4V power transformer. When the power of the transformer is 20W, 40W, and 60W, the load capacity of the voltage stabilizer is 110W, 220W, and 330W respectively; the four relays Kl~K4 use JZC-21F (T70) small relays, and the contact current has three specifications of 3A, 5A, and 8A. The corresponding specifications can be selected according to the load conditions of the voltage stabilizer; T2 uses an ordinary 3W power transformer with a secondary voltage of 6.5~7V; other components can be selected according to the parameters shown in the figure.