This doesn't make electrical sense.

flatheadfan

Well-known member
If you have your entire car original (6 volt positive ground) and wish to run an accessory such as a modern radio (12v, negative ground), you need a converter. I have used these in several cars over the years without ever experiencing a failure. This is where the puzzle comes in.

Since the radio is grounded to the cars' chassis it would seem that you would have a negative ground and a positive ground conflicting with each other which would lead to all types of gruesome possibilities. But, it doesn't happen. I need some help on this to understand it!

Thanks

Tom
 

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I would think the converter would have to have it's own ground. Are you saying there is just one wire from the converter to the radio? Don't see how that would work, it should require a return path.
 
I have the same setup for my lighter socket to charge my phone.

Wires or frame and any metal in the car is neither positive nor negative in and of itself. It's just a conductor used to complete a circuit and current path from a source that creates it. The inverter is such an independent power source. It sends a positive current to the radio and uses whatever the radio is grounded on to complete the circuit back to itself through its own ground. It is like a little negative ground battery operating independently of the battery. It doesn't matter that the battery is using a ground source to complete its positive ground circuit back to itself.
 
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Is there a converter that bumps the stock 6 volts up to 12 volt to power the radio? Where does the other 6 volts come from?
 
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I think you answered your own question when you ask it. Ground is ground, whether it is positive or negative. You always have a power side and a ground side.
 
I used a converter in my positive ground MG for many years. The only problem was when one of the speakers went bad it grounded and there was smoke from that speaker --- the radio and converter were ok
I did mount the converter in the spare tire compartment to hide the noise
 
Basically, if you double the voltage you halve the amperage.
in other words 6 volts at 10 amp current draw, gives you a 5 amp at 12 volt capability. The old style was just like a transformer. the "in" circuit is separate from the "out" circuit and the ratio between "in" and "out" depends on the number of windings in each. Just like your ignition coil.

In this case, twice as many windings on the "out" as the "in" gives you double the voltage. How ever nothing is free, so as said, the amperage able to be delivered is halved. I hope that helps.
 
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