Active triac triggering circuit

A power system for thermostats, comprising:

• a first terminal connected to a line of a power supply;
• a bypass circuit having an input connected to the first terminal;
• a triggerable switch having an input connected to the first terminal;
• a power steal module having an input connected to an output of the bypass circuit;
• a zero crossover detector having an input connected to an output of the bypass circuit;
• an energy storage module having an input connected to an output of the power steal module;
• and
• a trigger circuit having an input connected to an output of a zero crossover detector and having an output connected to a second input of the triggerable switch;
• and
• wherein:
• the trigger circuit comprises a processor;
• the processor has an input connected to the output of the zero crossover detector and an output connected to the second input of the triggerable switch;
• the power steal module steals power from the first terminal or an output of the bypass circuit;
• and
• the power steal module provides stolen power to the energy storage module.

A thermostat power system comprising:

• a triggerable switch having an input connected to a first terminal;
• a bypass circuit having an input connected to the first terminal;
• an energy storage module having an input connected to an output of the bypass circuit and an output connected to a second terminal;
• a power steal circuit having an input connected to an output of the triggerable switch;
• and
• an active trigger module having an input connected to an output of a wave position detector, having an output connected to the triggerable switch, and having an input connected to a second output of the energy storage module;
• and
• wherein:
• the first terminal and second terminal are for connection to an AC power line and load arrangement;
• the power steal circuit comprises transistors;
• a trigger signal is sent at certain times, according to information at the output of the wave position detector, from the output of the active trigger module to a second input of the triggerable switch;
• and
• a signal from the output of the triggerable switch to the input of the power steal circuit turns the transistors on or off;
• and
• wherein the active trigger module takes energy at the second input from the second output of the energy storage to trigger the triggerable switch near a zero crossing of the power line when energy directly from the power line is insufficient to trigger the triggerable switch.

A power supply unit for a heating, ventilation and air conditioning thermostat, comprising:

• a first terminal for connection to a line of a power source;
• a second terminal for connection to a load;
• a bypass circuit having an input connected to the first terminal;
• a triac having an input connected to the first terminal;
• a stealing circuit having an input connected to an output of the bypass circuit and having a first output connected to the second terminal;
• a power steal module having an input connected to an output of the triac;
• a trigger circuit having an output connected to a second input of the triac;
• a linear regulator connected to a second output of the stealing circuit;
• and
• wherein the second output of the stealing circuit is connected to a second input of the trigger circuit.

A power supply unit for a heating, ventilation and air conditioning thermostat, comprising:

• a first terminal for connection to a line of a power source;
• a second terminal for connection to a load;
• a bypass circuit having an input connected to the first terminal;
• a triac having an input connected to the first terminal;
• a stealing circuit having an input connected to an output of the bypass circuit and having an output connected to the second terminal;
• a power steal module having an input connected to an output of the triac;
• a trigger circuit having an output connected to a second input of the triac;
• a zero crossing detection circuit having an input connected to the first terminal;
• and
• an interface circuit having an input connected to an output of the zero crossing detection circuit and having an output connected to an input of the trigger circuit;
• and
• wherein:
• a second output of the stealing circuit is connected to a second input of the trigger circuit;
• the trigger circuit comprises:
• a DC-DC negative current source having an input connected to the second output of the stealing circuit;
• and
• a triac gate triggering signal circuit having an input connected to an output of the DC-DC negative current source
• a zero crossing signal goes from the zero crossing detection circuit to the input of the interface circuit;
• and
• a zero crossing drive signal goes from the output of the interface circuit to the input of the trigger circuit.