Substituting a Power Adapter?

Question

I'm looking at purchasing an old ethernet transceiver but it does not come with the power supply. The current owner says they used a 12V adapter from radio shack.

The company site says this on their Data Sheet:

Power Supply: 115 Vac at 30 watts

60Hz (220 V available)

Wouldn't I need a power supply that said 115V which is way more than 12 Volts?

Answer 1

The 115VAC listed on the website means it works in a standard, US wall outlet, alternating current or AC.  The 12V adapter is 12 volts direct current or DC.  It looks like a little "brick" and converts the AC coming out of the wall socket to a DC for the equipment.  The wattage, 30 watts, is the important bit.  You'll need to find an adapter that says something like 12VDC 30W output.

It's easy to find one and, I'd be willing to bet, you may already have one in your house.  Otherwise, Radio Shack has "universal" adapters that will do the trick.

Answer 2

The first owner should be right. The 115V is the input of the adapter. The adapter output is 12V which is needed by the transceiver.