Discussion in 'General Electronics Chat' started by teratron, Sep 24, 2008.

1. ### teratron Thread Starter New Member

Sep 22, 2008
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I have a car radio at home. It is model CD200 from Fujitsu ten ltd.I want to use it in my living room, put in a wooden box and a set of speakers. Now I want to buy or build a power supply to power the car radio, insted of use a car battery, I need a power supply 120vAC/12vDC regulated. I ask how much amperes is needed to power the car radio? Its out there any circuit available?

2. ### liitlefan New Member

Sep 24, 2008
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u don't need to consider amperes if you use an AC/DC convertor. but u should know the power of your radio,which should be smaller than the one convertor can supply.
but if you wanna build an circuit for your radio ,you need know it too.

3. ### beenthere Retired Moderator

Apr 20, 2004
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294
I don't get any hit on that radio. If it has a label giving wattage, divide that figure by 12 to get the current requirement. If it's above 10 amps, think about battery eliminators. These are brute force supplies that substitute for car batteries on a bench. They aren't really well regulated, but they are really cheap compared to a power supply.

4. ### teratron Thread Starter New Member

Sep 22, 2008
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thank you for the suggestions. I will try it and let you know.

5. ### mik3 Senior Member

Feb 4, 2008
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Find a power supply from a broken PC and use its 12 V supply. It can handle up to 8 Amps.

6. ### beenthere Retired Moderator

Apr 20, 2004
15,808
294
You might find that the HF noise from a SMPS is a bit intrusive in a radio.

7. ### Audioguru Expert

Dec 20, 2007
10,809
1,221
An ordinary modern car radio produces 14W RMS per channel when its two speakers are 4 ohms and its supply is 13.2V. So its output is 28W and its efficiency is about 60% so its total power from the supply is 47W. The max current is 47W/13.2V= 3.6A.

It is not operated at full power all the time so a 3A power supply with some big filter capacitors will work fine.

If you use a 12V supply then the power is much less.