softball question here
softball question here
(OP)
So I have an old stereo with an internal battery that runs on 7v 1.2 amps and its without a powercord. just so happens this radio is great for the beach because it has an internal battery, so I would like to rig up a charger to use in my truck. I know my truck delivers 12v 10amps max. If i include a fuse at say 2.0 amps for safety and a small capacity resistor to limit the current to 1.2 amps, should i be ok powering my stereo at 1.2 amps? With respect to the battery charge, is the only thing important the amperage and not the voltage?
I'm not a electrical guy, clearly. thanks in adveace.
I'm not a electrical guy, clearly. thanks in adveace.





RE: softball question here
Think of the wire coming from the battery as being a water pipe. Voltage is the pressure and Amperage is the rate of flow. Now think what happend when opening a facet a small amount. Only a certain amount of water will flow out but the pressure will remain basically the same. It's the same with an electrical circuit, the Voltage will be what it is, but the flow of current will depend on what it's hooked to. Lower the resistance (the valve being opened to allow more water) the higher the amount of current that will flow (the more water that will pass through the pipe).
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RE: softball question here
RE: softball question here
If you still wish to go this route, you should get a charger specifically for this battery and use it to buffer the voltage from the truck and prevent damage to your battery and system.
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RE: softball question here
First find out the voltage that your battery needs to charge. Then buy an integrated circuit voltage regulator. Don't forget that the regulator may be subject to 100 Volt transients.
Others here may provide more specifics on selecting and wiring a voltage regulator circuit.
Bill
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RE: softball question here
TTFN

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RE: softball question here
If so, then you can maybe (still?) purchase adjustable DC regulators that plug into a cigarette lighter socket (universal DC car adapter, example image embedded below) and slide the many-position slider switch over to the nearest voltage to 7 volts. 1.2 amps might be a bit high; most of these top out at 1 A...
If you can't find one, then you'll need to arrange a 7 volt PS. eBay has quite a selection of DC-DC converters (easily meeting these specs), but they would require some wiring and packaging.