Power stealing for a thermostat using a TRIAC with FET control

An electronic thermostat circuit with improved power stealing for controlling an AC control device, said circuit comprising:

• a source of AC control power coupled to an electronic switch means having an electronic switch means control input, the electronic switch means for controlling the AC control device;
• a diode bridge means, the diode bridge having an AC connection and a DC connection, the AC connection electrically coupled to the electronic switch means control input, the diode bridge for controlling the electronic switch means by a DC control signal applied to the diode bridge means DC connection;
• an amplifier means having an on state and an off state, the amplifier means electrically coupled to the diode bridge means DC connection, the amplifier means having an amplifier input for controlling the state of the amplifier and an amplifier output for generating the DC control signal;
• an isolated gate FET means electrically coupled to the amplifier input for controlling the state of the amplifier, the isolated gate FET means further electrically coupled to a digital input signal, the digital input signal controlling the state of the DC amplifier means, the isolated gate FET means powered by the current derived from the source of AC control power by power stealing;
• wherein the digital signal controls the state of the AC control.