There are many instances when it would be convenient to switch an appliance on or off remotely rather than switching it manually. Such circumstances include switching on pathway lights when you arrive home, switching garden and/or pool lighting on or off, and switching power to water pumps.

Remote switching can also be very convenient for appliances that are difficult to access, eg, in a factory.

The UHF Remote Mains Switch can switch loads of up to 1875W or 2500W - see text.

This unit was originally designed to switch mains-powered water pumps on and off in response to signals transmitted by the Water Tank Level Meter Base Station described last month. However, we soon realised that by adding a separate handheld transmitter to control the unit, it could also be used as a stand-alone unit for lots of other applications.

It’s quite simple really – if you want to team the unit with the Water Tank Level Meter Base Station, then you don’t need the handheld transmitter. That’s because a transmitter is built into the Base Station itself. Conversely, you do need the transmitter to use the unit in other applications – ie, without the Base Station.

By the way, commercial remote control mains operated switches are readily available for switching appliances rated up to 1000W. Typical of these is the Altronics Cat. A-0340 which can be used with up to five outlets and has a range of 20m.

However, if you want to switch devices rated over 1000W or control water pumps, then you need the UHF Remote Mains Switch described here. It can switch devices rated at up to 2500W over a range of up to 200m. That’s 10 times the range typically available from the low-cost commercial units!