Definitive 24V Gainclone Battery Supply Recharging? - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 8th January 2004, 03:06 PM   #11
mgreene is offline mgreene  United States
diyAudio Member
 
Join Date: Jun 2002
Location: Aiken, South Carolina USA
Default The Schematics Above

So, the question is - how many of the above does one need for 4 batteries, ie, a 24V+- gainclone? Is uneven charging an issue?

Mike
  Reply With Quote
Old 8th January 2004, 03:19 PM   #12
diyAudio Member
 
johnferrier's Avatar
 
Join Date: Sep 2003
Location: WA
Default I'm at square one...

...what batteries are we using to provide +/-24V?


JF
  Reply With Quote
Old 8th January 2004, 03:20 PM   #13
mgreene is offline mgreene  United States
diyAudio Member
 
Join Date: Jun 2002
Location: Aiken, South Carolina USA
2 X 7ah 12V sla's per rail.

Mike
  Reply With Quote
Old 8th January 2004, 03:57 PM   #14
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Default Re: The Schematics Above

Konnichiwa,

Quote:
Originally posted by mgreene
So, the question is - how many of the above does one need for 4 batteries, ie, a 24V+- gainclone? Is uneven charging an issue?
I originally charged my whole 6pcs Battery Stack from one charger in series. My batteries where all from the batch but had seen around 2 Years prior service in a Standby UPS that also charged them in series. The result was very uneven charging and discharging, as batteries had obviusly aged differently.

So I would for best battery life recommend for SLA's to be charged either parallel (which neccesitates a major switching logic) or with a simple charger per battery. As said, a single LM317 in I/V limiting mode with flyback diodes will handle charging the battery fine and will allow switching simply the Mains supply to the individual transformers off for "pure battery power".
Adding the chokes allows permanent (on all the time) charging without audible downsides I could percieve compared to previous applications. The result becomes basically a "battery buffered" rather than battery supply.

Sayonara
  Reply With Quote
Old 8th January 2004, 04:34 PM   #15
mikelm is offline mikelm  England
diyAudio Member
 
Join Date: May 2003
Location: England
Send a message via Yahoo to mikelm
After trying 4 batteries, + /- 24V shared between two channels I came to the conclusion that to avoid earthing / crosstalk compromises it is necessary to have 4 batteries per channel.

Hugh Dean made the point on another thread recently how important it is to have separate supplies for each channel.

I guess if the two channels and the batteries are all in one box it is marginally more acceptable to share supplies but if you want the best I think 8 batteries are needed

mike

p.s. using a transformer and diodes as a charger is not fixed voltage - it starts low and ends higher ! The current is high at first and then naturally drops down to a float type trickle at the end of the charge, so long as you choose the transformer with care.

P.P.S. DON'T FORGET THE FUSES !!!!!
  Reply With Quote
Old 9th January 2004, 01:22 AM   #16
diyAudio Member
 
Join Date: Jan 2003
Location: LA
Quote:
Originally posted by mikelm

p.s. using a transformer and diodes as a charger is not fixed voltage - it starts low and ends higher ! The current is high at first and then naturally drops down to a float type trickle at the end of the charge, so long as you choose the transformer with care.

P.P.S. DON'T FORGET THE FUSES !!!!!
But your charging voltage will be susceptible to changes in your AC line voltage, and SLA batteries don't like being overcharged, it will shorten their life. I would put in a voltage reg. as a minimum.

Randy
  Reply With Quote
Old 6th April 2004, 02:45 AM   #17
diyAudio Member
 
Join Date: Mar 2004
Location: athens ga
Mike, What would the specs be for a carefully chosen transformer? I was considering getting a custom wound transformer - 120VAC primaries, 1*34.5 volt AC secondaries, and about 1VA. I would use a single MU diode rectifier bridge. I would then trickle charge 4 12v 7A gel cell type batteries with 48 volts in series, at all times except when in use. (I would use two of these setups for isolated channels.) A single spst switch would turn off the charger when listening to music. Would gel cells be susceptable to uneven charging like Kuei Yang Wang mentions for SLA? I would only be able to listen 3 or 4 hours or so every other night max, so I would probably not need much current to maintain full charge. I would try to balance the mA to meet my needs. Are my assumptions correct? Will this work? In order to not over charge how many mA should I really end up with?
  Reply With Quote
Old 6th April 2004, 06:29 AM   #18
mikelm is offline mikelm  England
diyAudio Member
 
Join Date: May 2003
Location: England
Send a message via Yahoo to mikelm
This link may provide some useful background.

http://www.batteryuniversity.com/partone-13.htm

I personally would use one 9V + 9V transformer for each series pair of 12V batteries. This means that the charger is still valid if one of the batteries is in a different condition. I used 75VA transformers.

By careful choice of transformer I meant that you need a combination of transformer regulation and diode forward voltage drop so that at the end of the charge the voltage across the battery is within the limits stated for SLA mentioned in the link.

I would aim for the voltage at end of charge to vary between 13.5V and 14.0V with the variation in the mains supply.
  Reply With Quote
Old 6th April 2004, 03:54 PM   #19
diyAudio Member
 
Join Date: May 2003
Location: Duluth, Georgia
I just ordered 4 Panasonic LC-R127R2P1 to use with my "Peter Daniel/BrianGT" GC. I am going for a simple charger; I realize there may be some shortening of battery life, but I'd rather replace the batteries than spend a bunch of time on a super fancy charger.

I'm planning on using a Stancor P-8551 24v 1a transformer to charge each series pair of batteries. I'll use a LM317 vr to drop the voltage down to about 28. A DPDT switch (or a relay) to go from charging to listening.

David
  Reply With Quote
Old 24th March 2006, 04:32 PM   #20
JDeV is offline JDeV  South Africa
diyAudio Member
 
Join Date: Oct 2002
Location: Cape Town
Quote:
Originally posted by randytsuch
I am in the process of designing a SLA battery charger based on the TI UC2906/UC3906 chip. It is really pretty much designed, but I still have to draw up the schematic.

This chip will control the charging modes, which can be bulk charging, overcharge and float (trickle).

From what I know about SLA's, you can use a simple constant voltage circuit, but it takes longer, and you do sacrifice battery life when you use this scheme.

A "smart" charger is pretty simple to make using this type of chip, and besides, where is the challenge is building a voltage regulator? And, you can sample the chips from TI.

Anyway, I have all the parts, and the project is on my list of things to do, probably a month or two away though.


Randy
Hi Randy,
Did you ever complete this project? Can I view your design/ circuit - if possible?
__________________
"Be carefull who's advice you buy, but be patient with those who supply it."
From Baz Luhrmann's - Everybody’s Free (To Wear Sunscreen)
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gainclone with battery vs. A/C power chuck55 Chip Amps 5 3rd May 2007 11:54 PM
Battery powered gainclone grounding? abkingsbury Chip Amps 0 10th August 2004 04:51 AM
How much power will a battery powered GainClone produce? Tony D. Chip Amps 2 5th July 2004 09:20 PM
Battery Gainclone? chrille Chip Amps 17 13th October 2003 08:00 AM


New To Site? Need Help?

All times are GMT. The time now is 03:47 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2