Simple Adjustable Linear Power Supply dual channel

This power supply circuit is dual channel power supply. One channel is supply positive voltage and the other channel is supply negative voltage. It supply from voltage 0V to +/-15V. Maximum output current is around 1A (recommended). It limit by LM317 and LM337 voltage regulator.
This circuit is simple voltage regulator, where have not current limiting (output protection circuit). but, it is useful for who plan start the DIY electronic project or experiment.

This power supply using LM317 and LM337 is most simple power supply.
The board have some jumper, because I try to make the board small and quick.

The power supply schematic.
The input power transformer 230V to 15-0-15 (30VA)

You can download the layout.







Circuit BOM

Component	Quantity	Reference Designator
Transformer 30VA(min) output 15-0-15	1
Diode 1N4007	8	D1, D2, D3, D4, D5, D6, D7, D8
LED	2	LED1, LED2
LM317	1	U1
LM337	1	U2
Electrolytic capacitor 2200uf 50V	2	C1, C2
Electrolytic capacitor 10uf 16V	2	C5, C6
Electrolytic capacitor 1uf 16V	2	C7, C9
Resistor 1/4W 220R	2	R3, R5
Resistor 1/4W 150R	2 (will difference)	R11, R12
Resistor 1/4W 4.7k	2 (will difference)	R1, R2
Variable Resistor 2.5k	2	R4, R6
Variable Resistor 100R	2 (optional)	R4', R6'
Jumper	2 (will difference)	D11, D12
Reserve	4	C3, C4, C8, C10
Terminal Block

Circuit Explanation

Transformer
This is simple circuit, but, it still have a lot of basic knowledge inside. (for electronic newbie)
First, you have to understood how to choose transformer for you circuit. you can read post at below.
Understand transformer - basic

Reservoir Capacitor (filtering capacitor)
Link here