Dual adjustable power circuit

Circuit principle: This circuit uses a three-terminal adjustable integrated voltage regulator. When S is set to 1, the power
supply After bridge rectification, the AC voltage is sent to the inputs of IC1 and 1C2 respectively. terminal, through the control of the sampling resistors Ri, M and the adjusting potentiometers RP1 and RP2,
a continuously adjustable voltage of ±1.25-15V is obtained at the output terminal. When S is set to 2, the dual-group output power transformer T is used as a single group.
After the power supply voltage is rectified and filtered, only IC1 is sent to obtain
a single power supply output of +1. 25-30V. Among them, resistors
Rl, Rz: 240CZ, potentiometers RP1, RP2:
4.7kf2; capacitors cl, C: 3300FcF/150V, G,
C: 0.33_uF/63V.C5, C: lOtlFl50V;
diodes VD1~VD4: 1N4001, VD5～VD6:
1N4001} Three-terminal integrated block ICl: LM317． IC2:
LM337; switch S: KNX (Z×2).
  All capacitors in this power supply must have a withstand voltage greater than
50V. The power consumption of the two three-terminal adjustable voltage stabilizing blocks is about
15W. Pay attention to adding sufficient radiators.