sinewave oscillator

Cold weather is one of the banes of a motorist`s life. Not only must he worry about the car starting on cold winter mornings, but there is the added nuisance of frozen windscreens to cope with. To help combat this latter problem, many cars are fitted with heated rear windscreens. Usefu I though these are, it sti II means one has to wait until the heating element has warmed up sufficiently to melt the frost before being able to move off. The circuit described here is designed to assist the motorist in a `fast get-away`, by ensuring that the heating element is switched on before he reaches the car.