US 2015/0145347 A1 · LOW POWER CONSUMPTION AC LOAD SWITCHES

Abstract

A circuit for ensuring ultra-low power relay switching to control an AC load and extend a battery's lifetime. A control circuit may be designed to work where power is provides at very low duty cycle in that the on-time of applied voltage is quite short compared to its off-time. During the on-time, power such as that from a battery may be consumed to drive the circuit but overall such consumption of power is almost miniscule, for instance, a few microamperes or less from a three volt battery. An input FET may drive a pair switching FETs that provide pulses to a transformer which provides a ramp of voltage that remains above zero volts to a pair of AC switch FETs. An output of the AC switch may go to operate relays of a wire saver for operating one or more thermostats.

Claims20

Dependent claims

A mechanism for low power consumption load switches, comprising:

a switch having an input terminal for a low duty cycle signal having a duty cycle of less than ten percent, and having an output terminal for connection to a voltage supply;
a dual switch having a first input terminal connected to the output terminal of the single switch, a second input terminal connected to the input terminal of the single switch, and having first and second output terminals, respectively;
a transformer having a first end of a primary winding connected to the second output terminal of the dual switch, a second end of the primary winding connected to the first output terminal of the dual switch, and having a first end and a second end of a secondary winding;
and
an AC switch having a first terminal connected to the first end of the secondary winding of the transformer, a second terminal connected to the second end of the secondary winding of the transformer, and having third and fourth terminals.

2 more elements

A method for low power switching of a load, comprising:

providing an input FET for receiving a low duty cycle signal having a duty cycle of less than ten percent and for connection to a supply voltage, to be switched in accordance with the low duty cycle signal;
connecting an input of a high side FET to an output of the input FET;
connecting an input of a low side FET to a terminal for receiving the low duty cycle signal;
connecting a first end of a primary winding of a transformer to an output of the low side FET;
connecting a second end of the primary winding of the transformer to an output of the high side FET;
connecting a first end of a secondary winding of the transformer to an input of a first AC switch FET and an input of a second AC switch FET;
connecting a second end of the secondary winding of the transformer to a first terminal of the first AC switch FET and a first terminal of the second AC switch FET;
and
connecting a second terminal of the first AC switch FET and a second terminal of the second AC switch FET to an AC load.

6 more elements

Dependencies are inferred from the claim text.

Low power consumption ac load switches

Life of this patent

Low power consumption ac load switches

Life of this patent

Abstract

Claims20