ANDREW LAMBERT PHOTOGRAPHY / SCIENCE PHOTO LIBRARY ANDREW LAMBERT PHOTOGRAPHY / SCIENCE PHOTO LIBRARY
Dimmer switch. This is the inside of the switch. The working components of a dimmer switch consist of a rheostat (variable resistor, lower left). Turning a circular knob increases the resistance in the rheostat, thereby lowering the amount of voltage available to the light and dimming it. This is a somewhat innefficient solution, since a lot of power is lost as heat energy from the resistor. More efficient modern systems rapidly switch the electrical supply on and off to effect the same result.
Model release not required. Property release not required.