Electricity can be divided into categories, depending on how powerful it is and how it was designed to behave. There are three main categories you need to understand: AC vs. DC, Voltage and Hertz. Each one has the potential to make or break your network because most electrical components are designed to work only with specific types of electricity. Look at the back of a printer. There will probably be a single value for voltage (v) and for Hertz (Hz). If there is a range of values then the device will work with multiple values. For example, my printer will work only with 110v but with 50-60 Hz. But just what do these values mean?

Voltage is electrical pressure and is one component of total power. How much electricity a device gets is a function of the pressure forcing the electricity down the line. Voltage forces amperage (amps) into a device. The total power received is measured in watts and is equal to volts times amps. A 110v device receiving 1 amp just received 110 watts of power. A 220v device receiving 1 amp receives 220 watts of power. Same amount of power being transferred but because the pressure or voltage was twice the amount, the second device receives twice the effect. This makes it dangerous to plug a device that wants 1 amp and is rated for rated for 110v into a plug rated at 220v. The device will suck up 1 amp and will probably burn out because the pressure is too great. The reverse is also true but the device may not operate due to not receiving enough power.

Alternating Current (AC) and Direct Current (DC) may both be used to operate a device. AC operates in a sine wave where the voltage fluctuates from a positive peak to a negative peak. ON a circuit rated for 110v, the sine wave will fluctuate from +110 to -110 (The peak to peak value is actually higher because of the curvature of the wave). How often this wave cycles is the Hertz or cycle frequency. The western hemisphere mostly uses electricity operating at 60 Hz while the Eastern hemisphere mostly uses 50 Hz. This means that the fluctuation occurs more rapidly in the U.S. than it does in the U.K.

AC is the preferred method of delivering electricity because devices can be used to break the voltage down into smaller pieces. A transformer can be used to break 220v AC down to 110v AC. High voltage lines can be used to deliver 15,000v to a neighborhood and local transformers will break the electricity down for the homes. DC doesn't have the cycle variation, a 220v DC flow is always +220v. Because there is no variation, there is no way to break the voltage into smaller pieces. AC can be converted into DC simply by lopping off the negative voltage and smoothing out the positive peak but 50 Hz can't be changed into 60Hz.

Some devices are equipped to sense the incoming voltage, configure themselves and use it. Others don't have that mechanism built in. Other devices may run off DC voltage and won't care how the original AC was made. 50Hz or 60, it all gets turned into DC and the device using the electricity never notices. This is why most laptops, portable CD players and handheld game players can work anywhere. They run off DC and AC is used to recharge or for conversion.

The real problem people run into is with the Hz. AC can be used to create a magnetic field to keep a motor turning. If the Hz is incorrect, the motor will turn too fast or too slow. This may not be much of a problem with a small handheld drill but what does it do to a hair drier? You can set your PC's power supply to interact with 220v/50Hz but what about your printer? Will it work okay after the transformer has converted the voltage?

You can purchase transformers that will convert voltage from one value to another. Some transformers will only convert one way, say from 110v to 220v or vice versa and would be referred to as a step-up or step-down transformer. Others can transform voltage in either direction. You also need to know what the voltage is like where the work will be done. Japanese voltage runs at 110v while voltage up to 250 can be found in India and South Africa. There's typically a little bit of slop allowed, most devices from the US will run fine on the Japanese 100v, but be careful going up with precision devices.

Questions? Comments? Post your thoughts below!