In olden times, with resistance dimmers (see Dimmer, Resistance
), if the dimmer
was not loaded to within 75% of its capacity, the load would not dim completely to zero. Thus extra lights or heater coils were added to the circuit
, often backstage in a corner, to make up the additional capacity.
Even today with modern phase-control dimmers, a ghost load of 100W may be needed to allow dimming of a very small load, such as a string of mini Christmas lights or a 15W practical
lamp or dimmable LED
AKA dummy load
. Do not confuse with ghost light