The circuit described here is a kind of remote control for all sorts of equipment that must be started or switched on with the aid of a trigger pulse. The authoress actuates it with a flash of the headlights to switch on the garage lights When light falls on to the six series-connected solar cells, T1 is switched on, which results in T2 being switched off. Capacitor C2 is then charged.
When the light is removed from the cells, T1 is switched off and T2 is switched on. Capacitor C2 will then be discharged through the LED of the electronic remote which is consequently energized for the instant. in that way, trigger pulses are generated for electrical isolation and equipment without the need of an additional power supply.
In the diagram, C1, R1, and R2 ensure stable switching operation.
The solar cells used in the prototype gave an effective range of 2–3 m (7–10 ft).
The circuit is intended as a momentary action push button, not as a locking switch. The latter function may be obtained by adding, for example, a latching relay 
