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Showing posts from July, 2009

Variable DC Power Supply with 2N3055

This is variable power supply for multi purpose usage and very useful to supply your electronic tools or your projects. Voltage range will be 0.7 - 24V and the urrent limiting range is 50mA - 2A.

Components:P1____________500R Linear Potentiometer
P2_____________10K Log. Potentiometer

R1,R2__________2K2 1/2W Resistors
R3____________330R 1/4W Resistor
R4____________150R 1/4W Resistor
R5______________1R 5W Resistor

C1__________3300µF 35V Electrolytic Capacitor (see Notes)
C2_____________1µF 63V Polyester Capacitor

D1,D2_______1N5402 200V 3A Diodes
D3____________5mm. Red LED

Q1___________BC182 50V 100mA NPN Transistor
Q2___________BD139 80V 1.5A NPN Transistor
Q3___________BC212 50V 100mA PNP Transistor
Q4 _________2N3055 60V 15A NPN Transistor

T1____________220V Primary, 36V Center-tapped Secondary
50VA Mains transformer (see Notes)
PL1___________Male Mains plug
SW1___________SPST Mains switch

Notes:P1 sets the maximum output current you want to be delivered by the powe…

20A Regulated Power Supply

Here the regulated power supply circuit that will give you current output up to 20A depends the number of power transistor used in the circuit.

You can build the box like this:

here te schematic diagram:

for further instruction, visit this page

Dual Polarity Power Supply with LM317/LM337

This is a regulated dual polarity power supply (download schematic and pcb layout HERE):

The output of this circuit will be positif output(+), normal/ground output(0) and negative output(-). IC LM317 is used to regulate the positive output and LM337 is used to regulate the negative output. You should use TAP transformer for this circuit and heatsink for the IC.

Please visit this page for complete explanation
Another dual polarity power supply circuit, visit here

Variable Power Supply with L200

This inexpensive variable power supplycircuit with L200. The output current is up to 2A and the output voltage depends to the output voltage from transformer. VR 47R used for current adjustment and the VR10K used for output voltage adjustment.

1-32V Variable Power Supply based on LM338

This is regulated variable power supply circuit based on Transistor LM338. Short circuit protection added in this circuit.

1.3V-12.2V, 1A Variable Power Supply

This is a simple but reliable power supplycircuit based one of the oldest integrated voltage regulators of them all - the LM723.

Please visit this page for complete explanation.