Run 120v amp on 12v.

Projects General Guidance
1

Hi guys,

I've got a small home receiver that runs on mains voltage, and I was wondering how difficult it would be to convert it to run on 12v DC?

I know I could just use an inverter, but since it'll be run from a battery, my runtime would be very low.

Here's the transformer circuits from a service manual. Although these are from a 230v model, whereas mine is a 120v model.

2

Without seeing the rest of the power supply circuitry (L page 40?) I suspect by the number of secondary windings is that this receiver uses both positive and negative DC voltages. As such you would need some kind of DC to DC isolated inverter section to generate at least the negative and maybe both polarities if they are required to be higher then the +12volt available in a car. So your probably better off just considering a standard 12vdc to 120vac inverter of the proper wattage. Keep in mind that inverter use for audio service is often quite 'noisy' and distorted if not well designed and filtered.

Lefty

3

retrolefty:
Without seeing the rest of the power supply circuitry (L page 40?) I suspect by the number of secondary windings is that this receiver uses both positive and negative DC voltages. As such you would need some kind of DC to DC isolated inverter section to generate at least the negative and maybe both polarities if they are required to be higher then the +12volt available in a car. So your probably better off just considering a standard 12vdc to 120vac inverter of the proper wattage. Keep in mind that inverter use for audio service is often quite 'noisy' and distorted if not well designed and filtered.

Lefty

Hi Lefty,

I did some digging and it looks like it uses +15v, +10v and -7.5v.

I've decided to try out a $10 12v 60w amp from dealextreme. It's worth a shot for the money.