how to find the right power adaptor with limited information

[TRS45]

I need a power adapter  and the only information I have is that the power consumption is: DC 8V 4W and also the polarity is: +----( .----- - (minus). Can anyone help me with this??

[aha2940]

1W=1V x 1A, therefore if you know your device requires 8V and it's rated at 4W, you would need an adapter that can produce at least 0.5A.

Regards.

[Chevy49_be]

the polarity is: +----( .----- - (minus).

This means the outside of the pin (or the bottom side if its a PL01 or PL02 type) is positive. Most common adaptors have the opposite. As you can easily make a short with the outside of the pin. But if you find one with the right voltage, current rating and plug, its easy to change polarity by flipping both wires (on the dc side  )


In the table below you can look up the dimensions you have to find out the right plug: