| voltage doubler for small Aleph? - Click HERE for Original Thread |
| nobody special |
Would it be alright to use a voltage doubler for a small Aleph amp?
I was thinking of using 2 12.5V transformers with a doubler and a pi filter to obtain 23V rails. DuncanAmps PSU designer says that I will get 23V with 1mV ripple, which is about what I want. I know that doubler circuits aren't thought very highly of, but why not use one?
Steve |
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| jackinnj |
| quote: | Originally posted by nobody special
I know that doubler circuits aren't thought very highly of, but why not use one?
Steve |
No reason that a "doubler" or any other voltage multiplier should be thought <b> ill-of</b> -- as long as you realize that there is a trade-off between the multiplying and the number of joules you are periodically storing. In plain english, if the capacitors aren't big enough the output droops badly with increased current demand. |
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| nobody special |
Jens,
I was thinking of building some of those, but I really would like a little more power. Thanks for the suggestion.
Steve |
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| nobody special |
| quote: | | No reason that a "doubler" or any other voltage multiplier should be thought ill-of -- as long as you realize that there is a trade-off between the multiplying and the number of joules you are periodically storing. In plain english, if the capacitors aren't big enough the output droops badly with increased current demand. |
Do you have any guidelines for how to deteremine the capacitor ratings, etc?
I was using Duncanamps simulator, and used 6800µF caps for the double caps, and a bank of 68000µF for the first filter bank, a 2.5mH inductor, and then another 68000µF for the second bank. The ripple was very low. The only thing that worries me is the doubler caps... I don't know what values are appropriate, and what kind of caps to use. The caps in the doubler seem like they have a lot of power continuously going through them. What does this do to their life? |
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| moamps |
| quote: | Originally posted by nobody special
but I really would like a little more power |
Hi,
You have 4 transformer 12V/20A, 80 pcs 6800/25V caps, and you want to build some Aleph and get about 30W in class A. The best way to do this is building Aleph X; using 2 transformer for one monoblock, full bridge rectifier to get rails about +-16V and 20 caps 6800uF per rail (some inductor between maybe) and schematic with 8 output FET-s per channel. You will be maybe happy than with about 40 W pure class A.:nod:
Forget idea with voltage doublers, this principle can't work here OK (to much current). IMHO.
Regards |
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| moe29 |
I'd love to build an Aleph X, but i haven't been able to find
circuit art for a 1 sided PCB. (is it possible to do a 1 sided?)
Not all of us were here early enough to get it on the group PCB buy :( |
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| nobody special |
| quote: | Originally posted by moamps
Hi,
You have 4 transformer 12V/20A, 80 pcs 6800/25V caps, and you want to build some Aleph and get about 30W in class A. The best way to do this is building Aleph X; using 2 transformer for one monoblock, full bridge rectifier to get rails about +-16V and 20 caps 6800uF per rail (some inductor between maybe) and schematic with 8 output FET-s per channel. You will be maybe happy than with about 40 W pure class A.:nod:
Forget idea with voltage doublers, this principle can't work here OK (to much current). IMHO.
Regards |
That's pretty much what I decided to do. Actually, that is why I bought these parts in the first place. I really don't like the idea of making an AlephX with just 12 volt rails, which is what they are going to load down to with the 7 amps of bias I will be running. I was thinking about making a stereo X and using 2 trannies per rail to get about 25 volts, but my heatsinking is not up to the task.
Thanks for the replies!
Steve |
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