Audio Project Amplifier Speaker Loudspeaker Kit
diyAudio.com diyAudio Forums Archive > Top > Other Stuff > Everything Else
 
power supply compromises - Click HERE for Original Thread
nobody special
I have a bunch (80) of 6800µF 25Volt caps, 4- 12.5volt transformers. I would like to get a supply that will put out 25-32 volts for an Aleph amp (stereo), and I'm trying to figure out the best way to do it.
Should I:
A- use four bridges, 1 for each transformer, with caps (10x6800 per tranny/bridge) on the output of each, and stack the supplies in series to get my +/- voltage?
B- series the transformer secondaries, and use series pairs of caps with balancing resistors? (the caps would be too low voltage to use without series pairs like this).

I am leaning towards A, even though it will give me a little less voltage. I just don't like the idea of using caps in series, for some reason.
Is it alright to use two bridges for each transformer to seperate the channels somewhat? (total of 8 bridges!:bigeyes: )
Also, what is the appropriate way to connect the supplies together? I am using inrush suppressors off the bridges (CL-101, .5 ohms cold, approx .05 ohms with my current draw). I planned on making a circuit board to mount all the caps, and just have a common point in between supplies at the bridges/caps (one big plane). Any problems with this?
The plan is to mount the first capacitors/transformer/ bridges/ in a seperate enclosure, and then run short and heavy cables out to the two amplifier chassis'. In each amp chassis I will have a 2.5mH inductor, and then another 52000µF per rail.
Steve
nobody special
this is close to what I was thinking of doing (see attachment)
nobody special
This is closer to it... shows the paralleled bridges for each channel.
Sorry about the line quality- I'm using an early version of Acrobat. If you print it, it is much clearer.
Steve
nobody special
no opinions?

That would be a first around here, ha ha.
I guess I will just build the dang thing and see how it works!
moamps
Hi, Steve

I prefer first sch. Look at http://www.diyaudio.com/forums/show...ps&pagenumber=6 my posts about double rectifiers. Caps 52000uF/30V are little under voltage rated. From 2*12.5V AC, you get about 32-33V. Are secondaries of your transformer 12V/20A made with one single wire or with more thinner wires?
You need discharge resistors on caps too.

Regards
moamps
quote:
Originally posted by nobody special
The plan is to mount the first capacitors/transformer/ bridges/ in a seperate enclosure, and then run short and heavy cables out to the two amplifier chassis'. In each amp chassis I will have a 2.5mH inductor, and then another 52000µF per rail.
Steve

Hi,

I don't like this plan. I think that you will have problems with grounding scheme. Better solution in your case is using one big enclosure, one big heavy star ground point (one PS for two channel).

Regards

Page generated in 0.022331953048706 seconds with 17 queries,
spending 0.00555277 doing MySQL queries and 0.01677918 doing PHP things.

Powered by: Search Engine Indexer and vBulletin
Copyright ©1999-2009 diyAudio.com