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Why not batteries instead of power supplies?

I read about issues with power supplies, like noise from AC outlets, ripples in voltage etc.

Why not just use a large battery that can be recharged? If batteries can power cars, they can for sure power amplifiers.
defiantboomerang
kosst_amojan
2,095 posts
 
No doubt supercaps are expensive as all hell, but when you're talking about $50,000 amps, is $3000 really all that insane when it comes to filtering a power supply? I'm not suggesting using them as primary supply filter caps. I'm suggesting using them as an additional filter stage between the rectifiers and the common electrolytics. If you've got even 200 Farad between the filter caps and rectifiers, are you going to even be able to measure the ripple? Sure, you'd need massive inrush current control, and the thing might take 5 minutes to charge up, but that's really about as close as you're going to get to a completely hassle free battery with practically none of the drawbacks. 
larryi
1,972 posts
 

Kosst,

Use of a massive bank of capacitors does sound very interesting.  Have you tried this approach yourself?  Also, are they suited for constant drain (I thought they were primarily used where fairly rapid cycling is involved)?

georgehifi's avatar
georgehifi
4,966 posts
 
I used a capacitance multiplier circuit on a preamp once, worked very well, bit hard to do on a poweramp though.
http://electronics-diy.com/electronic_schematic.php?id=486

Cheers George 
guidocorona
4,114 posts
 

The new Rowland Power Storage Unit (PSU) is a full chassy external ultra-capacitor-based power supply. It has been designed to power simultaneously up to three line-level devices... A Rowland Aeris DAC, a Corus linestage, and as one spare output for future use.


I have had it in my system for about three months, and have applied it to my Aeris, as I am not currently using a line stage. The enhancement that PSU has brought to the system is rather phenomenal, for all audible parameters I can think of.... Its effect is tranformational: more in line with a substantive upgrade of all electronics, rather than the replacement of just one power supply.


Regards, Guido




kosst_amojan
2,095 posts
 
@larryi 
The ones Mouser is selling are designed for UPS backup power supplies. The main thrust of development for supercaps is to use them are replacements for batteries. A lot of gear already uses small supercaps for memory retention and running clocks in DVD players and the like. They replace button cells. I've never tried anything with supercaps in an amp. I'm not sure my amp building skills are to that point yet. I'd want to try it on a pre-amp first. Make a board and just hang up a half dozen or so of the little 2.7V 100 Farad deals and see how that works. Those are cheap. 
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