hi all
i have built a power supply using lm338T with NO HEAT SINK ...but then i tried it after i have finished building it, and it works perfectly with a motor 24vdc and 2.5-3 A.
Unfortunately the day after that i tried it again but it constantly delivering 42v out, after checking each component i found that the lm338T Vout and Vin pins are shorted .
i changed the lm338T and the trans 220 to (16-0-16) 3A with trans 220 to (12-0-12) 3A, But still the same..
This is circuit diagram
http://powersupply88.com/simple-vaia...a-power-supply
But without using the lm317 section (Current limiter)
Then i found that i was wrong in using LM33T without using heat sink (50C/W),
and found also that i must use LM338K with a suitable heat sink (1C/W)
Then i have decided to rebuild the following circuit:
http://www.eleccircuit.com/adjustabl...a-using-lm338/
Is there any advices before I start??
Im using a Trans 220 to (12-0-12) 3A
LM338K with heat sink
I have made calculations according to SgtWookie post in another thread and found that outputting 15v to 30v with 3A will be OK (15v through connecting a fixed Resistor series with the variable resistor).
Am I right??
i have built a power supply using lm338T with NO HEAT SINK ...but then i tried it after i have finished building it, and it works perfectly with a motor 24vdc and 2.5-3 A.
Unfortunately the day after that i tried it again but it constantly delivering 42v out, after checking each component i found that the lm338T Vout and Vin pins are shorted .
i changed the lm338T and the trans 220 to (16-0-16) 3A with trans 220 to (12-0-12) 3A, But still the same..
This is circuit diagram
http://powersupply88.com/simple-vaia...a-power-supply
But without using the lm317 section (Current limiter)
Then i found that i was wrong in using LM33T without using heat sink (50C/W),
and found also that i must use LM338K with a suitable heat sink (1C/W)
Then i have decided to rebuild the following circuit:
http://www.eleccircuit.com/adjustabl...a-using-lm338/
Is there any advices before I start??
Im using a Trans 220 to (12-0-12) 3A
LM338K with heat sink
I have made calculations according to SgtWookie post in another thread and found that outputting 15v to 30v with 3A will be OK (15v through connecting a fixed Resistor series with the variable resistor).
Am I right??