A compact inverter controller for varying the speed of AC & BLDC compressors in room air conditioners gives enormous energy savings in the appliance. Fitted in the outdoor unit of the split AC or at the back side of the window AC, the power controller varies the speed of the compressor in tune with the outside ambient temperature as well as the load on the AC unit. The set temperature in the room is maintained within close limits while simultaneously saving energy. Laboratory tests with leading AC manufacturers have shown around 35% and 50% energy savings for the AC and BLDC units. The logic for the speed selection with respect to temperature & load as well as the motor speed variation is done entire by software based controls resulting in a compact and reliable control unit which easily fits into the appliance. For split units there is a communication interface between indoor and outdoor units. The modified control card for the indoor unit incorporating the communication protocol, controls for blower/swing motors and the display unit is also available with the necessary remote interface. The controller complies with statutory and industry standards for safety, reliability and performance.

A front end Active Filter enables the unit to present near unity Power Factor at all loads and speeds. It also enables the appliance to operate from the mains which has a large fluctuations in the voltage - The Air conditioner will operate without any loss in performance even when the input supply voltage varies from 150 - 300 V, thereby totally eliminating the need for a voltage stablizer.

Different models with current rating of 10A, 15A, 20A and 30A are available and they are suitable for 0.75Ton, 1 Ton, 1.5 Ton and 2 Ton units with a cooling capacity of 9000, 12000, 18000 and 24000 BTU/Hour.