Energy conserving (stand-by mode) power saving design for battery chargers and power supplies with a control signal
A system is described that turns off a high power, power supply when a device no longer needs high power. A low power, power supply or a rechargeable battery provides power to determine when the device again needs high power. The low power supply consumes a minimum possible power when the device does not need high power and the power rechargeable battery is not charged. That is, the high power and low power, power supplies are turned on or off based on the real time power consumption need of the device and the charged state of the battery. The power need of the device is monitored by a current shunt monitoring circuit and a control signal monitoring circuit.
1. A power supply apparatus for a DC device, comprising:
an actuable AC to DC power supply for supplying power to the device and having a first power supply supplying the device and a second power supply; and
a control circuit, powered by the second power supply, for turning the first power supply on/off when the device is connected/disconnected from the apparatus and when the device does not need power.
2. A power supply apparatus for a DC device, comprising:
an actuable AC to DC power supply for supplying low and high power to the device; and
a control circuit for turning only the high power supply on/off when the device does not need power.
3. A power supply apparatus for a device that produces a control signal and receives power from a power source, comprising:
a first low power supply receiving power from the power source and supplying low power to the device;
a second high power supply receiving power from the power source and supplying high power to the device; and
a control circuit supplying the high power to the device and disconnecting the second high power supply from the power source responsive to the control signal.