0-50V 2A Bench power supply

Circuit diagram

0-50V 2A Bench power supply-Circuit diagram

I use the lm10 IC because it has a reference voltage and that’s useful for dc power supply. With two ICs can take different output voltage and amperage. This circuit is protected from short circuit.P2 is for controlling the current at the range of 0-2A. Stabilize the output voltage with R4 on negative pin on op-amp and with R2 & P1 on positive pin.

Op-amp output controls T1 that not let ripple of voltage.T1 increase or decrease ampere of R6 and control the voltage of T5 & T4. Pin 1 is the reference voltage and reference voltage is losing some voltage on R1 that has 100uA . This current passes through P1 too. Vlose p1=100uA*Rp1 This lose voltage regulate output voltage rate of output current is compare between reference voltage of P3 and lose voltage on R11.T3 is protecting short circuit with R11. For reduce out put voltage to 0v should parallel one resistor 470 ohm in out put. Minimum voltage is 0.4v. The maximum output voltage is fixed with R1b and should not become over of 50v. Therefore your transformer should give 36V, 3A with 4700uF capacitor. T6, T5, T7 need heatsilk.

0-50V 2A Bench power supply


  • R1a = 2,2 K
  • R1b = read the text
  • R2 = 10 K
  • R3, R7 = 3.3 k
  • R4 = 390 Ohm
  • R5 = 47 K
  • R6 = 3.3 K 1Watt
  • R8 = 180 Ohm
  • R9, R10 = 0.47 Ohm 3Watt
  • R11 = 0.075 Ohm 2Watt
  • R12 = 470 Ohm
  • P1 = 500K liner potentiometer
  • P2 = 4.7 K potentiometer
  • P3 = 10 K potentiometer
  • C1 = 1nF
  • C2 = 10nF
  • C3 = 22nF
  • C4 = 47mF 63v electrolytic
  • C5 = 4700mF 80v electrolytic
  • T1, T2 = BC161
  • T3, T4 = BD141
  • T5 = BD241
  • T6, T7 = 2V3055
  • D1, D2 = 1N4148
  • D3, D4 = 1N4001
  • IC1, IC2 = LM10C
author: hamed_iranmehr@yahoo.com
circuit from http://www.electronics-lab.com/