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Charging Circuit Answered

I was wondering if anyone had any ideas on how to make a circuit so that I could charge a battery, but that I can also power an amplifier when the battery is not charging. Currently I have a switch that switches between a charging circuit and powering the amplifier, but I was looking for a way to do this without having a switch that I have to control



4 years ago

Try this....


also, how would this change if I wanted to run a 24 volt battery and amp?

This circuit provides 24VDC by the LM317 regulator from the 30VDC input or the stand alone battery provides 24VDC and goes lower as it discharges.

The 50 ohm 2 watt resistor will charge a low ( say a discharged 20 volt ) battery with a 200ma current reducing to a maintenance charge of 100ma at 25v.

If you are using a small battery perhaps you will want to use a 200 ohm

resistor that uses a maintenance charge of 25ma.


This is exactly what I was looking for, Thank You!

Pleased to help.

You should include the your ability to understand circuit schematics and any other skills on your profile page.


What kind of modifications would I need to be able to power this for 24 volts instead of 12?

Sounds like the system need a larger charging circuit. One that can output enough power to run the amp and charge the battery. If the system has a switch to change between charge and battery then the manufacture skimped on the power supply.

You'll need to provide more information about the power needs of the system before anyone can help in redesigning the power supply for it.

I have a 12 volt amplifier that is designed to run off a 12 volt dc power supply. Currenty I am running it off a 12 volt sealed lead acid battery. I have a switch that will either direct the power from the battery to the amplifier or to a charging plug. I was wondering if it was posible to create a circuit that would not require a switch. Below I have included a simple diagram to show you what i mean about the switch

switch diagram.gif

actually the diagram is wrong. the base of the switch is at the battery and can change from the adapter and the amplifier