I am looking for a 28 - 0 -28 transformer. Anyone know what has such a transformer. I mean, I dont want to buy one for 45 bones, I want to get one off an old computer or blender.

I also need a 6.3 v transformer. Any ideas as to what has one of those ? Cell charger ? some other 6-7-8V battery charger ?

Cool.
Buddha.

I know if you use an old computer power supply, use the 12+ and 5+, using the 5 volt lead as the ground, it will produce 7 volts.  as for the other one, are you stepping down to 28v ?  if so, check out the box of transformers at your local goodwill-salvation army.  for example most 12v cordless phone power adapters actually put out around 16-18v

12v+ on the molex connector is yellow, 5v+ is red  fyi

you can also volt mod a vibrator using a PC power supply

Quote from: yamahonkawazuki on March 29, 2010, 11:37:54 PM
you can also volt mod a vibrator using a PC power supply

And run it on a 220 ... talk about a smile on the chicks face ...
Cool.
Buddha.

Quote from: jeremy_nash on March 29, 2010, 11:25:09 PM
I know if you use an old computer power supply, use the 12+ and 5+, using the 5 volt lead as the ground, it will produce 7 volts.  as for the other one, are you stepping down to 28v ?  if so, check out the box of transformers at your local goodwill-salvation army.  for example most 12v cordless phone power adapters actually put out around 16-18v

Now a cell phone charger power cord, it has a bunch of wires out of it right, what is the wiring convention on that ?
Some has a coax plug ... some others have this flat blade style, and yet others are like that littte T shape ...
Cool.
Buddha.

6.3 VAC will be in nearly anything old enough to have tubes - it's the common filament heater voltage. Almost nothing else you can easily scavenge from (assuming you have access to old enough scrap to easily scavenge those) will have that voltage. Nearly any transformer used in tube equipment will have a winding that does that voltage.

Good luck finding the 28-0-28 (aka a center-tapped 56VAC) without spending money.

Yea its for my wannabe tube preamp with chip amp.
Cool.
Buddha.

You might be aware (and you might not) that you can also use 2 separate 28V transformers to create the 56V center tap arrangement. Hook them up correctly, 56VAC across the two unconnected leads. Hook them up backwards, 0 (or nearly 0). Just check and swap if need be. Depending on design, you can often get away with a pair of transformers near the design voltage (ie, two 24 or 30 VAC), just don't use two that are different (one 24 and one 30 would be bad.)

Few computers in the past 20 years will have normal transformers to scavenge - they almost all use switching power supplies. You might find odd voltages like 28VAC in older modem or printer wall-warts. Look for big heavy wall-warts (or line warts) as those are more likley to be based around a standard 60Hz transformer. Small light ones are generally switchers, as are ones with multiple input voltages without changing a switch.

Yea someone already pointed me to a printer power supply.
And I didn't know that about using 2 of em.
The lm3886 is suppsed to be OK with 24-36 v supply.

6.3v ac transformer would be in a ~9v DC power supply right ? Yea warming the tube ...

Cool.
Buddha.