hi,
i need to know how can i reduce my transformer DC voltage?
now i have in secondary is 43-0-43 ACv. can it be reduce after rectified? like it is 59v dc after rectified. i only need 40v.
is it will be easy to make the circuit? i will need 40-0-40 DC volt.
my transformer is about 10amp.
thank you.
i need to know how can i reduce my transformer DC voltage?
now i have in secondary is 43-0-43 ACv. can it be reduce after rectified? like it is 59v dc after rectified. i only need 40v.
is it will be easy to make the circuit? i will need 40-0-40 DC volt.
my transformer is about 10amp.
thank you.
What are you powering with this power supply? How much current does it require?
You might look at this:
http://www.passdiy.com/projects/zenv3-2.htm
and this:
http://www.passdiy.com/projects/zenv5-7.htm
You might look at this:
http://www.passdiy.com/projects/zenv3-2.htm
and this:
http://www.passdiy.com/projects/zenv5-7.htm
Hi Space,
You mean the voltage after rectification and smoothing
If it's a Toroidal you can sometimes unwind a few turns off the secondarys. You could use a high power/current regulator but this is very inefficient, lots of heat at high current.
What are you trying to run off it.
Regards Karl
You mean the voltage after rectification and smoothing
If it's a Toroidal you can sometimes unwind a few turns off the secondarys. You could use a high power/current regulator but this is very inefficient, lots of heat at high current.
What are you trying to run off it.
Regards Karl
hi mooly,
actually it is for amp. i was supecting that i am overdriving the amp by voltage so it's need to reduce about 40+dc. it is not final yet. i am still testing on my amp now. see if there is anythings goes wrong. i already change one transistor for higher voltage as dx sugested. now operating it anschecking the temperature of the sink. it is now moderate volume about 41C. my sink is huge too.
it shouldn not be so hot till this, i still don't know, sound is clear too. i don't know how far the temp will go. what is the limit of the
temp for average amp.
my this transformer is good and heavy duty. it has 10amp power. i have like this two transformer. so i want to use it for amp i made.
thanks
actually it is for amp. i was supecting that i am overdriving the amp by voltage so it's need to reduce about 40+dc. it is not final yet. i am still testing on my amp now. see if there is anythings goes wrong. i already change one transistor for higher voltage as dx sugested. now operating it anschecking the temperature of the sink. it is now moderate volume about 41C. my sink is huge too.
it shouldn not be so hot till this, i still don't know, sound is clear too. i don't know how far the temp will go. what is the limit of the
temp for average amp.
my this transformer is good and heavy duty. it has 10amp power. i have like this two transformer. so i want to use it for amp i made.
thanks
Nordic.....wow....so great.
that means i am not operating over voltage. now i am testing for about 2hrs past... i am still operating on 59v....it's showing no problem so far, no extra sound....temp is now quite ok...39c in moderate vol....do you think this is correct temp? the problem was sove caused by thin cable i use for dummy test....also transistor...but that BC547..now BC546 transistor voltage still below 500mil volt....so i will chenk evn more prcly...
thanks nordic....again...
that means i am not operating over voltage. now i am testing for about 2hrs past... i am still operating on 59v....it's showing no problem so far, no extra sound....temp is now quite ok...39c in moderate vol....do you think this is correct temp? the problem was sove caused by thin cable i use for dummy test....also transistor...but that BC547..now BC546 transistor voltage still below 500mil volt....so i will chenk evn more prcly...
thanks nordic....again...
Hi,
Nothing very exciting really , I see Space keeps asking about and wanting to build amps with massive output stages, presumably for domestic use. Smaller really is better sometimes when it comes to audio.
I was going to say to connect a 'scope across your speakers, on a slow timebase speed, play music loud, louder than you ever would normally, and see what PEAK voltage you reach on transients. This gives you an idea of the maximum power you need to be aiming for and also an idea of the max rails you need. If you never hit more than say 30 volts peak, using rails of +/- 40 volts is probably all you need. It's surprising how little power you need, particularly with efficient speakers.
It keeps the design simple, costs are reduced, heatsink size is smaller etc.
It's very revealing -- try it . Would just add that as most scopes are earthed and so are most amps, be carefull. You may not even need the scope probe ground connecting at all if everythings earthed at the mains. A few mv of noise won't matter at all, if you need the ground perhaps use a 10 OHM in series with it just to prevent any problems--- there won't be.
Edit -- I mean 'scope probe ground NOT mains earth (The 10ohm bit)
Nothing very exciting really
, I see Space keeps asking about and wanting to build amps with massive output stages, presumably for domestic use. Smaller really is better sometimes when it comes to audio. I was going to say to connect a 'scope across your speakers, on a slow timebase speed, play music loud, louder than you ever would normally, and see what PEAK voltage you reach on transients. This gives you an idea of the maximum power you need to be aiming for and also an idea of the max rails you need. If you never hit more than say 30 volts peak, using rails of +/- 40 volts is probably all you need. It's surprising how little power you need, particularly with efficient speakers.
It keeps the design simple, costs are reduced, heatsink size is smaller etc.
It's very revealing -- try it
. Would just add that as most scopes are earthed and so are most amps, be carefull. You may not even need the scope probe ground connecting at all if everythings earthed at the mains. A few mv of noise won't matter at all, if you need the ground perhaps use a 10 OHM in series with it just to prevent any problems--- there won't be.Edit -- I mean 'scope probe ground NOT mains earth (The 10ohm bit)
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