Battery-powered supplies

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
It seems there are certain complexities in regard to battery charging(constant current, constant voltage, float charging , trickle charging, two-stage, three-stage etc) and I would be very happy if somebody pointed to where I can get some info on all this.
 
Batteries

I did some searching on the web. You can pick up 12V 7Ah batteries for about $20 apiece. Four of these would give 24 volt rails per side. That's $80. Then a charging system is needed. I'm still looking for an economical solution. I think that this is relatively inexpensive compared to buying the transformers and capacitors needed to make a quality power supply.

If Peter Daniel is listening, I know you use high quality caps in your stuff. Any thoughts?

Vic
 
Batteries? Hell Yeah!

I really like this idea of using batteries. I have used them alot in powering tube ampiliers, especially DHT. I am fond of the Panasonic LC-R127R2P (12V 7.2A) You would only need to put 2 in series for a single channel or 4 for a stereo jobber. So my question is how much current does the gainclone draw? How long would a setup using these batteries play? Also when using batteries do you still need the 1000uf caps and diodes? I hope Peter is using these same batteries on his setup and will tell us how they worked out. I Personally think car batteries would be a huge overkill. IMHO
Guiness
 
Re: Batteries? Hell Yeah!

Guiness said:
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
 
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.
 
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 ?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.