A socket timer is an interface device that provides timed power switching when installed between an electrical socket and the plug of an electrically powered product. These devices feature built-in timers that can be programmed by the user to switch power on and off at various, preset times. These timers have a standard electrical plug on the rear of the device and feature a replica electrical socket and a timing device — either digital or analog — on the front. They are designed to plug directly into an electrical outlet as a self-controlled switch between the power source and an electrical device.
These timers can be used to switch on lamps at various times throughout the evening, acting as a theft deterrent should a property be unoccupied. These power-switching units are also utilized to turn on electrical devices as required. It is possible to reduce energy consumption through the use of a socket timer as well as save money.
Control over power switching can be used to save electrical costs. As an example, in the United Kingdom, an electrical tariff exists — known as economy-seven — which provides heavily discounted electricity costs between the hours of midnight and seven o’clock in the morning. By using a socket timer to control when an electrical appliance is switched on, it is possible to make use of these lower electricity charges. Energy consumption savings can also be made by restricting the amount of time that an appliance is either standing idle or in standby mode but still using a small electrical charge.
Setting of a socket timer is achieved through the use of either a digital or analog control panel mounted on the unit. Analog systems take the form of a wheel that can be rotated to show the correct current time. Several small teeth are situated around the outer edge of the wheel, which can be clicked into a raised position to allocate the times during which the appliance is to be switched on.
These teeth are normally spaced to allow controls to be set at 15-minute intervals. When plugged into the main supply, the wheel rotates at a constant speed, passing through four teeth over a period of one hour. Passing over a raised tooth triggers a circuit switch that allows the current to pass from the fixed electrical socket through to the socket timer connection. Digital timers work in a similar fashion but utilize a simple digital display to allow setting of current time, start times, and finishing times.