Schematic Diagram:

Component List:
C1 = 2000uF per AMP, 40V (adjust capacity to power supply amps)
C2,C3,C12,C15,C18,C21 = 0.1uF CER
C4 = 0.01uF CER
C5A,C5B,C5C,C5D = 0.01uF CER
C6,C7 = 0.05uF CER
C8 = Not used
C9,C11,C19,C20 = 1uF CER
C10 = 470uF 15V EL RADIAL
C13 = 4.7uF 50V EL RADIAL
C14 = 0.001uF CER
C16,C17 = 22pF CER

D1,D2,D4,D5 = 1N4148
D3 = 1N4004
Br1 = 1<10A BRIDGE RECTIFIER (adjust seize to power supply amps)
DZ1 = 1N4751 30V ZENER
IC1 = LM317KCS TO220
IC2 = LM337LZ TO92
IC3 = LT1491CN special HV opamp, do not substitute
IC4 = PIC16F876A
Q1 = 2N3906
Q2A to Q2D = TIP142TU 1 to 5 transistors (adjust quantity to power supply amps)
Q3A to Q3D = 2N3904 (adjust quantity to power supply amps)

X1 = 20 mHz HC49 DigiKey PN: 300-6042-ND

LED1 = T1 3/4 RED OR GREEN LED
LCD = LCD, 2X16, HD44780 intelligent controller DigiKey PN: 67-1758-ND insulate from case

P1 = 500 Ohms
P2 = 10 kOhms
P3,P4 = 5 kOhms

R1 = 1 kOhms 10W
R2 = 1.5 kOhms
R3,R11,R12,R13,R14,R16,R17,R25,R26,R27 = 10 kOhms
R4 = 56 Ohms
R5A to R5D = 0.22 Ohms (adjust quantity to power supply amps)
R6,R28,R29 = 47k Ohms
R7 = as per schematic (adjust value to power supply amps)
R8 = 240 Ohms
R9 = 270 Ohms
R10 = 390 Ohms
R15 = 39 kOhms
R18 = 39 kOhms
R19 = 8.2 kOhms
R20,R22,R23,R32 = 1 kOhms
R21 = 5.6 kOhms
R24 = 33 Ohms 1/2W
R30,R31 = 4.7 kOhms

SW1 = SPST min toggle
SW2,SW3,SW4,SW5,SW6,SW7,SW8,SW9 = NO_SP push button
T1 = 24 V 1<8A (adjust seize to power supply amps)
T2 = 6.3 V, 150 mA

MISC:
3 Terminals
Transistors Heat Sink, up to: 1A = 30W, 2A = 60W, 4A = 120W, 8A = 240W to dissipate
Line filter, Case PCB, IC sockets…

PCB Layout:

Top side:

Bottom Side:

SPECIFICATIONS

VOLTAGE:

• Ajustable from 0 < 25 Volts at a resolution of 100 mV.

CURRENT: choice of 4 ranges;

• 0 < 1.000A at a resolution of 1 mA. JP1 and JP2 open, C1 = 2000uF filter cap., R7 = 0.5 Ohm, T1 = 24V, 1Amp.
• 0 < 2.000A at a resolution of 2 mA. JP1 ground and JP2 open, C1 = 4000uF filter cap., R7 = 0.25 Ohm, T1 = 24V, 2Amp.
• 0 < 4.000A at a resolution of 4 mA. JP1 open and JP2 ground, C1 = 8000uF filter cap., R7 = 0.125 Ohm, T1 = 24V, 4Amp.
• 0 < 8.000A at a resolution of 8 mA. JP1 and JP2 ground, C1 = 16000uF filter cap., R7 = 0.0625 Ohm, T1 = 24V, 8Amp.

2 lines LCD display:

• The top line shows the settings, the maximum current stays displayed at all times, it is not necessary to short the output terminals to set the maximum current.
• The bottom line shows the measured values.
• The arrows at the bottom center line show who is in control, the voltage or the current.

Adjustments:

• Voltage, steps of 1 V and 0.1 V.
• Current, steps of 1, 2, 4, 8 mA and 50, 100, 200, 400 mA depending on the Amp range.
• Memorisation of the last settings before power off, restarting with thoses same settings.

Download the full document include schematic diagram, reference, pcb layout and program source code :
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