James Webster
Fri 02 March 2007, 20:28
Total cost to build the 300VA power supply was:
AN-3225 (http://www.toroid-transformer.com/AN-3225.pdf) transformer $33.50
two 5600uf 100v caps $10.00 ($5 each)
USPS priority shipping $11.35
=============================
subtotal $54.85
All of the above came from http://www.toroid-transformer.com/
They shipped the next day
Here is the hookup guide to the AN-3225 based power supply for USA:
120V power comes in through the IEC Jack.
Neutral conductor connects to both black transformer wires
Hot conductor connects to one leg of circuit breaker.
Circuit breaker connects to both red transformer wires
AN-3225 transformer has two 25V AC output windings (refer to picture for letter codes)
(A) green conductor goes to ~ symbol on rectifier
(B) blue is connected to (C) green. This is the ONLY way you can get 50V AC, no other pair will work!
(D) blue connector goes to remaining ~ symbol on rectifier.
Rectifier has a chopped corner to mark the + output. If you really look hard the - is marked on opposite side. You now have 50V DC.
Two 5600uf 100V (uf is pronounced MICRO FARAD) capacitors are soldered together in PARALLEL (that means positive to positive, negative to negative). The + conductor from the rectifier runs across the positive terminals of the capacitors, the - conductor from the rectifier runs across the negative terminals of the capacitors.
At the end of these two conductors you measure 71V DC.
Notes:
1. If you mix up the B+C windings on the transformer, it will overheat and could start a fire, BE CAREFUL and get it right the 1st time.
2. The capacitors hold their charge even after the power is off. They can zap you even years later. A bleeder resistor could be added to drain them after power is cut.
3. The rectifier should be mounted to a metal plate to dissipate heat (it will last longer that way).
4. Be sure to use a fuse or circuit breaker.
USUAL DISCLAIMER: THIS STUFF IS DANGEROUS. I SUGGEST YOU DO NOT FOLLOW THESE DIRECTIONS AND JUST BUY A POWER SUPPLY. I CAN NOT BE RESPONSIBLE IF YOU DO NOT FOLLOW MY ABOVE ADVICE
http://www.mechmate.com/Forum/messages/17/3631.jpg
I already had a rectifier KBPC2502($1.75) and four-way fuse block 43-214($3.49) from http://www.hosfeltelectronics.com/ where shipping on a whole box of junk was $7.00 .
AN-3225 (http://www.toroid-transformer.com/AN-3225.pdf) transformer $33.50
two 5600uf 100v caps $10.00 ($5 each)
USPS priority shipping $11.35
=============================
subtotal $54.85
All of the above came from http://www.toroid-transformer.com/
They shipped the next day
Here is the hookup guide to the AN-3225 based power supply for USA:
120V power comes in through the IEC Jack.
Neutral conductor connects to both black transformer wires
Hot conductor connects to one leg of circuit breaker.
Circuit breaker connects to both red transformer wires
AN-3225 transformer has two 25V AC output windings (refer to picture for letter codes)
(A) green conductor goes to ~ symbol on rectifier
(B) blue is connected to (C) green. This is the ONLY way you can get 50V AC, no other pair will work!
(D) blue connector goes to remaining ~ symbol on rectifier.
Rectifier has a chopped corner to mark the + output. If you really look hard the - is marked on opposite side. You now have 50V DC.
Two 5600uf 100V (uf is pronounced MICRO FARAD) capacitors are soldered together in PARALLEL (that means positive to positive, negative to negative). The + conductor from the rectifier runs across the positive terminals of the capacitors, the - conductor from the rectifier runs across the negative terminals of the capacitors.
At the end of these two conductors you measure 71V DC.
Notes:
1. If you mix up the B+C windings on the transformer, it will overheat and could start a fire, BE CAREFUL and get it right the 1st time.
2. The capacitors hold their charge even after the power is off. They can zap you even years later. A bleeder resistor could be added to drain them after power is cut.
3. The rectifier should be mounted to a metal plate to dissipate heat (it will last longer that way).
4. Be sure to use a fuse or circuit breaker.
USUAL DISCLAIMER: THIS STUFF IS DANGEROUS. I SUGGEST YOU DO NOT FOLLOW THESE DIRECTIONS AND JUST BUY A POWER SUPPLY. I CAN NOT BE RESPONSIBLE IF YOU DO NOT FOLLOW MY ABOVE ADVICE
http://www.mechmate.com/Forum/messages/17/3631.jpg
I already had a rectifier KBPC2502($1.75) and four-way fuse block 43-214($3.49) from http://www.hosfeltelectronics.com/ where shipping on a whole box of junk was $7.00 .