Feb 19, 2013


Since my page was first posted, I have received a number of emails asking about a high current power supply. I looked around, but couldn't find one that was suitable. So, I designed this. It is a linear supply, which might have a few of you rolling your eyes, but it takes very few parts, is simple to build and can supply huge currents. 

This is the schematic of the High Current Power Supply



Total Qty.
R11680 Ohm 1/4 Watt Resistor
C1120,000 - 50,000uF 20-40 Volt Capacitor
C2, C32100uF 50 Volt Capacitor
C410.1uF 50 Volt Capacitor
C510.01uF 50 Volt Capacitor
D11Zener Diode (See Notes)
Q112N3055 Or Other (See Notes)
T11Transformer (See Notes)
BR11Bridge Rectifier (See Notes)
S11SPST 250 VAC 10 A Switch
MISC1Case, Line Cord, Heatsink For Q1, Binding Posts For Output


  1. D1 should be rated at about one volt higher than then desired output of the supply. A half watt diode will do.
  2. Q1 can be a transistor similar to the 2N3055. I chose the 2N3055 for it's availability and power handling (150 watts).
  3. T1 should be about 5 volts higher than the desired output of the supply, and rated for about one amp more of current. The voltage overhead is required by the regulator section. The extra current is to keep the transformer from over heating.
  4. The choice of BR1 will depend on the voltage and current of your transformer. The rectifier should be rated for 50 volts more than the transformer, and 5 amps more than the transformer.
  5. The value of R1 will be smaller when supplying high currents. Expiriment until you get what you need.
  6. You are going to need to heatsink Q1 and BR1. Use a small PC case style fan unless you are going to run large heatsinks.

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