Good'ay, I currently have a 60 Watt incandescent bulb (230VAC 50 Hzs) on my verandah. It is switched via a motion sensor, and only operates at night due to the incorpoation of a photoelectric cell. My problem is that, when I am away from home, if the bulb element blows I then have no verandah light. Please help me to work out a relay circuit (with or without additional items such as Rectifier Bridge, Smoothing Capacitor, etc.) which will operate in the event that the filament in the primary bulb blows, so as to energise the back-up one. T.I.A.