This is the schematic diagram of variable power supply.
The output voltage of this power supply circuit can be adjust from 0V to 28V DC, while the current output is static the rang is about 6A up to 8A.
Parts List:
- 2 x 15 volt (30volt total) 6+- amps
- D1...D4 = four MR750 (MR7510) diodes (MR750 = 6 Ampere diode) or 2 x 4 1N5401 (1N5408) diodes.
- F1 = 1 Amp
- F2 = 10 amp
- R1 2k2 2,5 Watt
- R2 240 ohm
- R3,R4 0.1 ohm 10 watt
- R7 6k8
- R8 10k
- R9 47 0.5 watt
- R10 8k2
- C1,C7,C9 47nF
- C11 22nF
- C2 two times 4700uF/50v
- C3,C5 10uF/50v
- C4,C6 100nF
- C8 330uF/50v
- C10 1uF/16v
- D5 1N4148, 1N4448, 1N4151
- D6 1N4001
- D10 1N5401
- D11 LED
- D7, D8, D9 1N4001
- IC1 LM317
- Two 2N3055 transistors
- P1 5k
- P2 47 Ohm or 220 Ohm 1 watt * (be sure you can reach 0 ohms as any resistance limits the current)
- P3 10k trimmer Calibration:
Source : belgacom.net