Dimming fluorescent ballasts and dimming LED drivers often use 0–10 V control signals to control dimming functions. In many cases, the dimming range of the power supply or ballast is limited. If the light output can only be dimmed from 100% down to 10%, there must be a switch or relay available to kill power to the system and turn the light completely off. Some 0–10 V controllers offer a built-in line voltage relay, others require an external line voltage relay. Some 0-10 V controllers, usually called 0-10 V Blink'n'Dim adapters, create a 0-10 V control signal in response to short blink signals from the power switch. Depending on the application, these options should be considered.