Three 300 Watt bulbs and three 500 Watt bulbs are connected to modulated infrared photocells, which are connected to
electronic on/off controllers. The 300 Watt bulbs are switched on till one or more person/s intermit one or more of the
infrared field/s and one or more of the 500 Watt bulbs is/are then switched on and off according to prescribed intervals
which represent certain dimensions of the installation/space.
Photo: H. T. Kratzmann