Patent ID: 10921014

Abstract:
Apparatus to continuously charge a smart thermostat battery and enable control of a 2-wire millivolt gas fireplace/heating system or a Heating, Ventilating, Air Conditioning (HVAC) system with at least one 24 VAC control voltage signal. The apparatus comprises one diode in a thermostat element or at least one terminal with a diode and a switch in the smart thermostat, and two diodes and a switch device in a switch element. The apparatus is configured to conduct a rectified current signal to charge the smart thermostat battery, and the at least one rectified 24 VAC control voltage signal to energize the switch device to control a HVAC system. The apparatus may be integrated into a smart thermostat with a graphical display to provide simple instructions to easily install the apparatus and the smart thermostat for a HVAC system without a common wire or a 2-wire millivolt gas fireplace/heating system.