December 13, 2011

Energy Efficient TV with 0 Watt Standby Mode

Toshiba Corp is reportedly releasing a 32 inch (visual size) LCD TV model "Regza 32BE3" equipped with its so-called "Eco Chip." The Eco Chip consumption current is said to be as low as about 95μA. This chip is used to detect ON signals from the remote control after the TV is turned off. It cuts off the AC power entirely through a relay as if you an unplugged TV. As the result, the power consumption in standby mode is 0 watt. The relay and the sensor that receive signals from the remote are powered by a large storage capacitor. Unfortunately, the report does not state the size of this capacitor and what happens when you leave the TV off for a long time. I guess either the chip needs to turn on the relay and re-activate standby bias supply before the cap is discharged too low, or you would need to turn on the TV by hand if the cap is discharged. Also they did not state power consumtpion or internal power supply efficiency in active mode (I wonder if they use bridgeless PFC front end?) In any case, such a "zero power standby" circuit is cute, but it is nothing more than a marketing gimmick. Obviously, you need to charge the storage cap during on-mode of the TV set. Whatever energy you save in 0W standby mode you need to spend to put this energy into this cap.