Seems to be just a full-bridge rectifier and capacitor voltage divider. Just wondering how well it works:
How much current can you get out of it? It says 25A rectifier, but not sure about output current.
Just wondering how well it works:
nts&hash=item565a0b676b
ure about output current.
what's interesting about it? it is just a standard rectifier cap combo
they just went overboard with the number of parallel caps, audiopholery or maybe they just got them cheap
-Lasse
snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
It also says "input voltage:AC 12V". Its not a PSU, its just a bridge rectifier + bulk capacitor filter to be used with a big transformer. 12 to 15A would probably be OK
-- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL
It's probably a typo. I think they mean AC -> 12V.
No transformer. In the connection picture, they wire it direct to the power amp. There is a small transformer on the right, but it's probably a separate circuit.
Idiotic. Those long skinny PCB traces will dominate the output impedance.
Are the caps 220u or 330u?
Some audiophool will like the way it sounds, I guess.
Is that a fake tube in the pic halfway down?
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
On a sunny day (Sat, 9 Aug 2014 08:39:02 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :
It would be better to use real capacitors with screw terminals:
Any bridge will do if it meets the current, but beware of the peak charge current. Anyway I see a 'tube' in that picture so somebody perhaps tries to sell 'HIGHER FIDILITY", and sub 10 Hz audio. In that case if that is your thing better use gold cables too. For an audio amp it makes NO SENSE whatsoever, as the feedback loop will get rid of the ripple that is already minimal in a symetrical design. Take botton ripple om max power and that is your peak to peak output voltage minus teh chisp intermnal drops, not clear what chips they use, look up spec. C is recharged every 10 mSs in Europe, Q = C.U = i.t
25 A and 20,000 uF and 10 mS ??? U = (i.t) / C U = 25 * .01 / (20*10^-3) = 12.5 V ripple 12.5V ripple on 63 V or is it 2 x 31.5 V...(just a wild ballpark) mm, seems something is wrong! You need a bigger C :-) or have less power available!
And I do not think those chips in that picture actually draw 25A ... Mine works great with 80 W:
So do not waste your money.
math OK? Mine works! No tubes.
I don't see the trace. But they are just connecting adjacent caps (probably all in series), it could be very wide traces.
It says 220u and 220u x 90 = 20,000u.
-A
_Com
12V AC in, +/- ~17V DC out
wer
rate
the transformer just isn't on the picture, you'll need one
-Lase
. Just wondering how well it works:
t sure about output current.
e.
ly all in series), it could be very wide traces.
there's a clear picture of the board,
it is just s standard bipolar supply, all caps in parallel half for + half for -
-Lasse
OK, i misunderstood this board. But would it work if the caps are in series, as i originally expected? Let say drawing 2A to 3A from the center of a capacitor voltage divider, away from the line and neutral (which could be reversed sometime).
It's good for maybe 1 amp output, with 1 volt p-p ripple at 50 Hz line frequency. It's absurd.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
what's interesting about it? it is just a standard rectifier cap combo
they just went overboard with the number of parallel caps, audiopholery or maybe they just got them cheap
-Lasse
++++++++++++++++++++++++++It still needs a center tapped transformer.
tm
That would only work for the AC component, not the DC.
-- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
'you need to weld the components"
Oxy-acetylene or electric arc?
I like how those caps look Nichicon brown, but are supposedly made in Taiwan.
Lasse Langwadt Christensen wrote in news: snipped-for-privacy@googlegroups.com:
OK. That's a real P.O.S. Should have been double sided with a continuous ground plane and a split power plane for the + and - banks.
-- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL
Not hard to solder along the tracks though.
NT
Apparently this would be good for +/-55 V output. Where did that 12 Vac come from ?
There are those 2 x 2 x 1 cm bridge rectifiers with a hole in the middle for the mounting screw that are sold at "25 A" or even "35 A" rectifiers. Since there are always two diodes conducting and the single voltage drop at least 1 V, the package dissipation is 50 - 75 W, which requires a good heatsink. That black heatsink in the picture might be good for 10-15 A.
A dual sided board or some big jumpers would have reduced the inductance significantly, instead of trying to use a single sided board without jumpers.
Nope. Putting 90 220uf caps in series yields ~ 2.4uF - what good is that?
Ed
There are 45 caps in parallel, two banks, V+ and V-. So each bank has 9900 uF or maybe 14,850 uF. Good for an amp or so.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
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