What do alternating current and direct current have in common?

Answer 1

Alternating Current (AC) refers to electricity where the Voltage on the "Hot" wire fluctuatesaround a particular level. Those levels common in the USA are 120 volts, 240 volts or 480 volts but can be other higher values for commercial power transmission i.e. 5,000 volts, 12,500 volts ect.

These voltages are actually referred to as RMS values or Root Mean Squared.

RMS refers to a mathematical formula that "averages" the fluctuations to a value. Actually .707 times the maximum value gives the listed value.

Direct Current (DC) does not flucuate the same way and in very well filtered, leveled off, electricity it can be almost a steady unvarying level. This is common in computer systems and medical equipment.

Both AC and DC Electricity flows on one wire goes through the equipment and comes back on another wire "completeing the circuit".

In your home AC comes in on one wire goes through a light switch and when the switch is turned on goes through a light bulb then out the other side of the light bulb on the "return" or "neutral" wire to your power panel and then to the ground to complete the circuit.

DC is functionally the same design for a light circuit. the difference is DC is steady at the level while in the USA AC fluctuates higher and lower around the listed voltage at a rate of 60 times a second or 60 hertz (hz). thats why you can sometimes hear bulbs "sing" or buzz. If you ever went to a concert and heard the AC power sneak through the sound system it sound like a low burrrrrrrrr sound.

You can hear the AC 60 hz sound near high power lines on the towers quite often.

Electricity is rated as volts, amps and watts for both AC and DC and in sufficient quantities both can kill and injure you.

Volts is what you see when electricity "jumps" from one thing to another.

Amps is what actually powers the equipment to do work. Think of a power tool or a vaccuum, both plug into a 120 volt outlet (the voltage) but a vaccuum that is 12 amps doesn't pick up as much dirt as a vaccuum rated at 20 or 30 amps that suck up your carpet.

Watts is a rating of the combination of volts and amps together. Confusingly referred to as "power" . This is usually used for speakers and radio amplifiers because they run off of different voltages and other factors so watts becomes easier to understand.