As the name suggest, a time switch is a switch that can switch ON or OFF automatically on a specified and configured time. It is normally used for street lighting, compound lighting, corridor lighting and where ever there is need for the lights to come on at certain hours of the day.
There are two main types of time switches and the most common one is the one that has a clock built into the switch. The motor is similar to the motor of our house clock and all the user has to do is to set the time for the lights to go ON and the time for the lights to go OFF. When the clock’s mechanism reaches that specified time, it triggers the switch inside to spring into a close circuit position. The opposite happens when the time comes for the lights to go OFF.
The disadvantage of switches like these is it needs to be reset-ted each time there is a electrical outage as the clock stops running with electricity. That is the reason we sometimes see road lights shining in the middle of the day. The technicians has not reset-ted the switch after shutting it down for maintenance.
Due to this handicap, another kind of time switch is slowly gaining popularity. This type of switch don’t rely entirely on electricity to run. It has a gear mechanism built in so that even if there is a blackout, the gears kicks in and keeps the clock running. It works just like the old fashion watch where we have to wind up each day, except in this case it is kept wound up when there is electricity.