Battery-powered supplies

[karma]

yes i saw the guts of a mark levinson amp that had batteries
it sounded great thay were sealed led acid. like the one's in ups's.
car batteries and motorcycle cells give off a gas that is really explosive not a good thing around eletronics

[vic2]

The UPS batteries I saw are sealed lead acid (SLA) types. Aparently, they are spill proof and do not emit gasses.

Vic

[Steve Eddy]

Originally posted by Guiness
So my question is how much current does the gainclone draw?

Quiescent (idle) current is only between 30-70 milliamps. Using +/- 24 volt supplies, you'll be able to swing about 20-22 volts typically, which into 8 ohms is about 2.75 amps peak.

Just be aware that using two batteries in series will halve their Amphour rating.

How long would a setup using these batteries play?

It really all depends on how efficient your speakers are and how loud you like to listen. Using some 7.2 Ah batteries, you should be able to get a good 8 hours of them easily. I'm in the habit of switching over to the charger when I'm not listening so I've never really tested to see just how long you can go without a charge in my particular situation. Suffice to say, I've never been interrupted by having to charge the batteries.

Also when using batteries do you still need the 1000uf caps and diodes?

Nope.

se

[Steve Eddy]

Originally posted by vic
Aparently, they are spill proof and do not emit gasses.

Wish I could have said the same at dinner tonight.

se

[Da5id4Vz]

I have a very old copy of the “Audel’s New Electric Library”. It’s a little leather bound pocket tradesman’s handbook filled with tons of technology history. If you ever have a chance to get pick one up, whether on radio, electricity, or carpentry, grab it! You wont regret the education. Another great book to grab would be a first edition copy of the “Audio Cyclopedia”.

I mention this because I am sure that in one of these that there is a great section on sound motion picture projection. The article describes the proper operation of the motor generator set, to insure that the lead acid cells are fully charged before the show begins.

I’ll see if I can’t scan it and post it. Might take a few days. Life is a little busy right now.

[Nisbeth]

Originally posted by Steve Eddy

Just be aware that using two batteries in series will halve their Amphour rating.

Steve, two 12V/7,2Ah SLA's in series yield 24V/7,2Ah, and using them in parallel yields 12V/14,4V, right?

/U.

[Audiofanatic]

Not right! in parallel 12V/14.4 Amp's
I think that you meant that!

Audiofanatic

[protos]

There is a nice IC for charging circuits by TI/Unitrode the UC2906/3906. However I can't seem to work out a proper circuit for charging 8 x 7,2Ah 12V batteries from the application notes.It's abit confusing. Can anyone help?

[protos]

Another thing that confuses me with batteries is that you would seem to need 4X the Ah for 24V than for 12V according to ohms law. However that may not be absolutely necessary in actual practice if you do not intend to run your amp flat out most of the time. If you are only swinging a few volts most of the time like me ( around 4 to 10V maximum) then this means you might not need so many more batteries if you go from a 12V supply to a 24V supply.Is this correct ?

[karma]

i have a few cells here. ill look for a working schematic. test it
and if it works get back to ya