Shared Knowledge

"Power Adapters - Use the Correct One"

18 October 2009

Summary: They are everywhere now: power adapters. There is one for the cell phone, one for the computer printer, one for the wireless router, one for the laptop, one for the iPod, one for the camera battery charger, one for the rechargeable drill etc. etc. AND THEY ARE ALL DIFFERENT!

I thought it was universal knowledge, genetic, but apparently it is not.

JUST BECAUSE A POWER ADAPTER'S PLUG FITS INTO A DEVICE DOES NOT MEAN IT IS THE CORRECT ADAPTER FOR THE DEVICE!!!!!

USE THE WRONG POWER ADAPTER FOR A DEVICE AND EITHER THE DEVICE WILL NOT WORK OR YOU WILL DESTROY THE DEVICE OR THE ADAPTER.

Power adapter 101:

- The power adapter supplied with a device is the one and only one you should be using with the device. As power adapters are never marked very well, it is easy to mix up adapters and devices, I suggest you mark each adapter as to its specific device as soon as you get the device and adapter.

- Voltage. Devices require an adapter supplying a specific voltage. Adapters usually convert house AC power to some DC voltage. DC voltages supplied could be 3, 5, 7, 9, ? volts. Use the wrong voltage power adapter and you could destroy the device.

- Polarity. DC voltage has a polarity meaning there is a "+" and a "-" terminal. Some adapters have the "+" on the center pin of the adapter device plug and some have the "-" voltage on the center pin of the adapter plug. You plug an adapter into your device with a plug polarity different than the device and you could absolutely destroy the device.

- Current. A device draws electrons from the power adapter. The amount of the flow is referred to as current. If you plug an adapter into a device and the voltage is correct and the plug polarity is correct  and the adapter can supply more current or electron flow than required by the device, no problem. But if you plug an adapter into the device that wants more current than an adapter can supply, the device may work for a while but eventually the adapter will fail.

So, the bottom line: (1) use only the adapter that came with the device; (2) mark each adapter as to its intended device when you first get the device and adapter.

If an adapter does fail, you can usually order another adapter from the device manufacturer or there are "universal" power adapters that let you set a specific voltage and change plug types and plug polarity. Just make sure you get  a universal that can supply the amount of current required by your device.