Capacitive drop power supply with low power consumption

A capacitive drop power supply circuit having low power consumption during a standby operating condition of a home appliance, comprising:

• a rectifier connected to an AC power source and operable to convert an AC power signal to a DC voltage;
• a current limiting capacitance interposed between the AC power source and the rectifier;
• a low voltage output stage having an input connected to the rectifier and an output connected to a microcontroller, the low voltage output stage operable to supply the DC voltage from the rectifier to the microcontroller and the microcontroller operable to monitor an operating condition of the home appliance;
• a higher voltage output stage connected in series with the low voltage stage and having an output terminal for connection to a higher voltage load, the higher voltage output stage operable to supply the DC voltage to the output terminal;
• and
• a shunt circuit path connected in parallel across the higher voltage output stage and configured to receive a control signal from the microcontroller, the control signal indicative of the operating condition of the home appliance and the shunt circuit path operable to reduce real power consumption during a standby operating condition of the home appliance.

A capacitive drop power supply circuit for use in a home appliance, comprising:

• a rectifier electrically connected to an AC power source and operable to convert an AC power signal to a DC voltage;
• a current limiting capacitance interposed between the AC power source and the rectifier;
• a low voltage output stage having an output terminal for connection to a low voltage load, the low voltage output stage receiving the DC voltage from the rectifier and operable to output the DC voltage at the output terminal;
• a higher voltage output stage having an output terminal for connection to a higher voltage load, the higher voltage output stage connected in series with the low voltage stage and operable to output the DC voltage at the output terminal;
• and
• means for phase shifting the AC power signal, thereby reducing the real power consumption of the power supply circuit

A method for reducing real power consumption of a capacitive drop power supply circuit in a home appliance during a standby state of the home appliance, the power supply circuit having at least one resistive element for dissipating power under a no load condition;

• comprising:
• monitoring an operational status of the home appliance;
• supplying power from the power supply circuit to electrical components of the home appliance during an active state of the home appliance;
• and
• shunting power across the resistive element of the power supply circuit during a standby state of the home appliance.