If you buy the wrong power supply you could cause substantial harm to your electronics, yourself and possibly cause a fire. If you buy the correct power supply then you should get trouble-free use of your electronics for quite a long time. Here are some great tips on how to buy a power supply the right way. This is written not by someone who sells power supplies or is doing someone who does a favor. This is written by a licensed ham radio operator that recently needed to think through the process of how to buy a power supply.

The first consideration is how much power you will need. There are three considerations to correctly determine the amount of power you will need.

· One consideration is what type of power your power supply will use as an input and output. Most of us are familiar with what we ham radio operators call a “wall wart”. A “wall wart” is the type of converter that plugs directly into your house’s AC outlets (wall outlets). They usually are small plastic box-like plastic contraptions with a small power cord and plug at the other end of it. You probably have used one for a radio, cassette player or other small device from time to time. In this instance, the AC (alternating current) is being converted to DC (direct current).

· Another consideration is what voltage you will need. Do not assume that one “wall wart” with the same size plug will work just as well for your device as another. Your power supply must be matched specifically for the device you are powering. If you supply your electronic device with either too much voltage or not enough you can cause serious damage to your device and possibly yourself. Be sure to check your device’s manual and / or stickers to determine the correct voltage needed. Do not assume that as long as your power converter supplies close to the right voltage that it will be good enough. That assumption can be quite dangerous!

· A third consideration is the number of amps (also known as amperage) that your power converter will supply. Think of it this way. Assume there are two people to handle a length of coiled rope. One person, call him “electronic device”, is pulling power (the rope). Another person, call him “power supplier”, is uncoiling the rope and letting “electronic device” take the rope that he is handing to him. If “electronic device” pulls the rope faster than “power supplier” is handing it out (supplying it) then “power supplier” is bound to wind up with burned hands from the rope being pulled too fast. This is just about what happens to the electronic components and power cord for your power supply if it is asked to supply too much power. This is where fuses and circuit breakers should step in to prevent things from going too far. Don’t take dangerous chances – get the right match for your equipment.

Also determine if there are other, less basic considerations. For example, in ham radio, some power supplies cause interference to some ham radio bands while others do not. Some large power supplies have noisy fans while others use cooling fins and heat sink devices to keep the power supply cool. Some power supplies for the same voltage and amperage are smaller than others because of a design that can wear out faster than other designs.

Look for unbiased write-ups by people who have used your choice for a long time. Search for internet forums for these write-ups. Make sure to read a good selection of these write-ups. In ham radio I use http://www.eham.net/reviews/ – there may be something like this for your particular application.

Remember – there usually are trade-offs in electronics design. For example, a smaller light weight more portable power supply may not be as durable and dependable for long periods of operation as a heavier unit with the same voltage and amperage specifications.

Once you have your model in mind determine how quickly you need your power. If you have the time, shop on the internet to find the best combination of price, freight and shipping times. Also remember to check for guarantees, warranties and availability of repair services. Good luck!