turning an old car stereo into a garage stereo.

[earlyre]

Originally Posted By: HerrStig
A cheap, (not well filtered) 12V power supply feeding a motorcycle size battery will be clean enough to run car audio gear. The battery acts like a many microfarad capacitor. A battery in good shape draws very little current (the float current) when fully charged and doesn't provide much in the way of additional load. It also provides good "dynamic regulation" -- providing a large amount of current for output peaks. A sealed or AGM battery won't be a big leakage problem. Remember, though, a rechargable battery is a bucket, you have to put back what you take out.

sooo back to my question of how to wire it up/what else do i need to acquire so's it will recharge the batt while the psu is operating, with out "overcharging" it, or killing the battery? (small 12v 5Ah sealed unit with "F1" or spade terminals on top. commonly used in UPS units, and home security systems)

 

[exranger06]

What do you need the battery for? Just connect the constant power and switched power wires from the stereo together, then connect them to the power supply.

 

[Cujet]

Originally Posted By: exranger06
What do you need the battery for? Just connect the constant power and switched power wires from the stereo together, then connect them to the power supply.


In the case of the small unit I built, the battery was 100% necessary to provide the surge power necessary for loud, power-hungry bass. The unit worked on a small battery charger without the battery, but distorted under heavy load, and the display went dim. Plus, some "hum" was audible. The battery filtered that out quite well.

 

[earlyre]

sorry to bring back an old thread, had put the project aside for a while.. now re building it in case #3....
first was an old(AT) tower pc case i had lying around (same one i harvested the PSU from)little bit of internal mod, case on it's side, the stereo fit right in. got everything wired & put together, didn't like the way it looked...
back to the battery box i had mocked it up with before, top wouldn't stay put with the cuts i had made, so.. $9 later picked up a plastic 19" Stanley tool box. everything fits fine, still haven't quite figured out a "tie down" solution for the battery yet..
speaking of the battery..
Originally Posted By: exranger06
What do you need the battery for? Just connect the constant power and switched power wires from the stereo together, then connect them to the power supply.

except the PSU WILL be switched off when not in use, and this being a fairly modern (JUST pre-MP3) all the settings (time,radio presets, EQ settings, etc) are lost if the power is disconnected. so a battery is needed for ease of use.

 

[earlyre]

as for keeping the battery charged, i got an inexpensive(~$20) float charger/maintainer from harbor freight(one of the better reviewed ones) currently wired thusly:

THIS is the charger i got.
and yes, i assembled an AC plug in a metal housing inside the tool box, with the "pigtail" being a standard PC style power cord, with the funny end snipped off.

 

[Kiwi_ME]

You might try experimenting with the memory power by measuring the current draw and the lowest voltage it will accept before dropping out. It may work with a much smaller, lower voltage battery which could be either not rechargeable or a 6V SLA recharged off the 12V with a 5.1 V zener diode in series.

 

[exranger06]

Originally Posted By: earlyre
sorry to bring back an old thread, had put the project aside for a while.. now re building it in case #3....
first was an old(AT) tower pc case i had lying around (same one i harvested the PSU from)little bit of internal mod, case on it's side, the stereo fit right in. got everything wired & put together, didn't like the way it looked...
back to the battery box i had mocked it up with before, top wouldn't stay put with the cuts i had made, so.. $9 later picked up a plastic 19" Stanley tool box. everything fits fine, still haven't quite figured out a "tie down" solution for the battery yet..
speaking of the battery..
Originally Posted By: exranger06
What do you need the battery for? Just connect the constant power and switched power wires from the stereo together, then connect them to the power supply.

except the PSU WILL be switched off when not in use, and this being a fairly modern (JUST pre-MP3) all the settings (time,radio presets, EQ settings, etc) are lost if the power is disconnected. so a battery is needed for ease of use.


Why don't you leave it plugged in and keep the power supply switched ON all the time? When you want to turn the stereo off, push the power button on the stereo, same as you would if it was installed in a car. You won't lose any memory settings and again, no need for a battery. Sorry, but I think you're making this WAY more complicated than it has to be.

 

[earlyre]

Originally Posted By: exranger06

Why don't you leave it plugged in and keep the power supply switched ON all the time? When you want to turn the stereo off, push the power button on the stereo, same as you would if it was installed in a car. You won't lose any memory settings and again, no need for a battery. Sorry, but I think you're making this WAY more complicated than it has to be.

1)I never said anything about unplugging when not in use.
2)not really building for me, was building for brother's garage, and knowing him, he will turn it off when he's not using it. he turns all his electronics off when not in use, he claims it's for heat build up in the house (Dallas, 30+yr old central air unit).
3)yes, @ this point i could lose the 2nd toggle switch, were it not already wired in, and the hole already drilled in the tool box.
I'm not MAKING it more complicated, it's already MADE. all i need to do is figure the batt tie down, and find smaller female disconnects for the speaker connections. (the ones there now, just slide off the spades, they are the larger of 2 "available" sizes, but it seems to be the only one anyone stocks in these parts....suppose i could just solder the wires into place..)
heck i already took one layer of complication out! I had wanted to have an unused USB hub hooked up for charging duties. ...couldn't get it to power up...