Using a power supply of LOWER voltage than the device claims is required will not harm it. What might happen however is that the radio may simply not work.
The other important consideration is current consumption. You need to ensure that any power supply you use can deliver, at minimum, the same current as the device requires. Having a higher rated current capacity in the power supply is OK.
Current and Voltage combine to define the power consumption of the device. So if you use a lower voltage power supply and it does actually work you need to increase the current capacity in proportion. So if the radio states it needs 12V at 1 Amp you will need a 2Amp power supply at 6V to deliver the same power. (12 Watts in each case).
Then there is the issue of AC and DC. It may be the radio has it's own AC to DC conversion circuitry - hence why it states it needs a 12V supply but only runs at 6V on batteries. A DC supply might work in that instance - but don't count on it. But if you plug an AC power supply into something requiring DC then it definitely won't work properly - if at all!
You can usually tell what type of supply it needs. A DC supply will be indicated by a flat line (or lines) after the voltage figure eg 12V -- . An AC supply will be indicated by a curly line, eg 12V ~
There should also be a label somewhere or a page in the manual that specifies what external supply you need. So simply use one of the same voltage and AC or DC as appropriate with a current rating equal to or higher. Most universal power supplies come with a choice of plug and changable polarity (for DC only) so this shouldn't be much of an issue.
By the way when I refer to AC or DC above that is the OUTPUT current of the power supply. Obviously the Mains side will be AC
Last edited by chrisjr : 25-08-2006 at 11:35
