Smart-home device switching circuitry with integrated power stealing control

A smart-home device comprising:

• an energy-storage element that stores energy that is harvested from an environmental system;
• a power wire connector and a return wire connector;
• a solid state relay (SSR) switching integrated circuit (IC) comprising:
• one or more switching elements configured to operate in:
• a first operating state in which the one or more switching elements create a connection between the power wire connector and the return wire connector;
• and
• a second operating state in which the one or more switching elements interrupt the connection between the power wire connector and the return wire connector;
• and
• a digital control circuit that controls the one or more switching elements, wherein the digital control circuit is configured to:
• cause the one or more switching elements to operate in the first operating state to activate an environmental function of the environmental system;
• determine that an electrical property of the energy-storage element has dropped below a first threshold while the one or more switching elements operate in the first operating state;
• in response to determining that the electrical property of the energy-storage element has dropped below the first threshold, cause the one or more switching elements to operate in the second operating state;
• harvest energy from the environmental system while the one or more switching elements operate in the second operating state;
• determine that a first time has elapsed since the one or more switching elements began operating in the second operating state;
• and
• in response to determining that the first time has elapsed since the one or more switching elements began operating in the second operating state, cause the one or more switching elements to operate in the first operating state.