Make Your Own Power Supply !!

Power supply is foremost important thing for any electronic hobbyist. Making one variable voltage power supply at home is extremely simple. You need just few components and one pretty nice transformer which can wholeheartedly supply enough current for your needs while staying cool !!.

LIST OF COMPONENTS :

1)Transformer	0-18 Volt, 1 Amp [ alternative: 9-0-9, 1Amp]	1
2)LM317 – variable voltage regulator	1.5A (TO-220 package)	1
3)Diodes	1N5408 1N4007	4 2
3)Capacitors	2200µF(or more),50V(or more) 470µF,50V(or more) 10µF,50V(or more)	1 2 1
4)Resistor	220E, 1/4 W	1
5)Pot	D25 Male	1
6)Grid PCB	3″ x 3″(approx)
7)Connecting wires	-	-

 CIRCUIT DIAGRAM :

NOTES :

• Do not use transformer with output more than 0-18 V (or 9-0-9), because their no load voltage goes upto 22-28V depending upon manufacturer. If you use higher o/p voltage transformer (say 0-24) its no load voltage may reach to 35-40V, which will damage LM317, once LM317 gets damaged, it will short i/p to o/p and full voltage will get connected to your circuit under test, thereby ruining the circuit.
• C1 should be as large as possible to get very good power supply ripple rejection.
• C2 and R2 should be soldered as close as possible to LM317· Heat sink is recommended for LM317.
• Try to obtain transformers current rating which is at least 1.5 times your maximum requirement. If u drive transformer considerably long time at its maximum rating it will become quite hot.
• Use plastic tape to properly cover AC mains and transformer connection. Slight carelessness here would lead to a nasty shock.