What can I do with this tranny?

[ThSpeakerDude88]

hey I've got a transformer laying around, was wondering what voltages I can get out of it after rectification. Its 24vac @ .8 amps center tapped, and 11 vac @ 1 amp ct. So, +/- 12 volts and +/- 5.5v I'm assuming. I know rectification of an ac voltage rasies voltage, but how much voltage can I get total +/- out of the 24v ct section, and at what amperage?

 

[cowanrg]

its probably not enough current to do a whole lot with. maybe a preamp or xover circuit? most likely not enough juice for an amp though.

 

[ThSpeakerDude88]

ok. It was used to power a TDA2050 and some rohm 10 watt chip in a 2.1 system. Big waste of space if you ask me.

 

[cowanrg]

after rectification you will get a factor of about 1.4 time the original voltage. so, you would get 33.6V out but still at 0.8A.

 

[paulb]

You can run a small amp with it. Surprising how little power you need in most situations. Average listening levels are probably something under 1 watt.

 

[ThSpeakerDude88]

well my pocket amp runs on a 32 volt 940 ma psu with no problems, accept of cource for diminished power output. So technically speaking I could build up to a 26 watt amplifier (33.6 x .8) with this power supply, like the TDA2040, or even the TDA2050 run at a lower voltage?

 

[ThSpeakerDude88]

p.s. how do I rectify it? I have a bridge rectifier that came off the amp board it powered, as well as some 12 volt + and - regulators.

 

[cowanrg]

here is a good example from decibel dungeon.

An externally hosted image should be here but it was not working when we last tested it.

 

[ThSpeakerDude88]

ok. Thanks! Looks pretty simpl, But , the fuse board is still attached to the transformer. It only had 2 wires in........I dont think it has a ground wire, does that matter, should I just follow the digram below for the rectification?

 

[cowanrg]

it only has two wires into the transformer, or two wires into the fuse board?

maybe a picture could help? but either way you should be fine and the diagram above should still be applicable.

 

[ThSpeakerDude88]

into the tranny. red-black-red out for thr 24vct, yellow-yellow for the 11v ac , its not ct i guess.

 

[cowanrg]

oh ok. just hook it up as the diagram shows and you should be fine. just use the 24vct and leave the 11vac tap alone.

 

[ThSpeakerDude88]

ok will do, Thanks! Gots one more question though: is the 24vct AC or DC? it has 2 red wires and a black (ground) how do I tell without a mm? does it really matter if its dc or not if I rectify it? and how much voltage can my rectifier handel? ok Im done askin questions

 

[asgorath]

Just a quick little suggestion...but save up your pennies and go buy a multimeter. I can't believe you're in the electronics hobby without one. Impossible to diagnose even a fraction without this basic meter.

 

[ThSpeakerDude88]

LOL save the warning for someone who doesnt know it. I know I need one... I just don't have 25 bucks to go out and blow right now. Maybe for christmas or birthday.

 

[cowanrg]

wow, you do need a multimeter... ill get back to that.

transformers simply transform the size of voltage due to a ratio if that makes sense. so, if you give it 120vac and it gives you 12vac out, its a 10:1 ratio. its just rated at 120vac input, but techincally, its just a ratio. you could give it 220vac in, and get 24vac out.

it does not however change AC to DC. that is for the rectifier, diodes, etc... the tranformer just changes the size of the voltage.

now, back to the multimeter thing... you MUST have one for this hobby, period. there are tons of people saying you need a scope, variac, etc... but, you CANNOT build anything sucessfully without a meter. i would put the hobby on hold until you can get one. look for used ones at garage sales, maybe friends have them for sale, etc. there should be a way to get one really cheap. hell, mow some lawns in the nieghborhood lawns or something

there is ALWAYS a way to get some cash for your hobby legally.