
How Does a Dimmer Light Work?
A dimmer works so that it pulses out current to the lamp. Each time the current drops to zero, ie when the alternating current changes direction. (50Hz AC passes through the zero point 100 times per second, once up once and once down for each period then the dimmer restricts the current so that it remains zero for a moment, how long is determined by how much you dim. Then the dimmer releases at full power for the rest of the period. This is repeated for each of the 100 periods every second. The finesse of this is that as long as the current is throttled to zero, there will also be no power loss (power P = U x I, I is zero, the power will be zero). And when the dimmer opens fully, current flows through the dimmer, but then the voltage across the dimmer is zero (or almost 0), the e...