A power saving device is described that is disposed in use between a further device and a mains power supply for supplying power to the further device. The power saving device includes: a communications channel input connected in operation to a communications channel output of the further device. The communications channel input is operable to receive control instructions from the further device. The power saving device also includes: a switch for disconnecting the further device from the mains power supply in response to the control instructions received from the further device; and an internal power source operable to provide power to the power saving device.