Systems and methods for enhanced efficiency auxiliary power supply module
Provided is a power supply for use in a solar electric production system, including: a first stage having an input connected to a voltage from a photovoltaic panel and an output providing a first voltage different from the voltage from the photovoltaic panel; and a second stage connected to the output of the first stage, the second stage supplying power at a second voltage to a micro-controller, where the output of the first stage is turned on and stable for a period of time before the second stage is turned on to supply the power at the second voltage to the micro-controller.
1. A power supply, comprising:
a first stage having an input connected to a voltage from a photovoltaic panel and an output providing a first voltage different from the voltage from the photovoltaic panel;
a capacitor coupled to the output of the first stage;
a second stage connected to receive power from the output of the first stage and from the capacitor, the second stage supplying power at a second voltage to a micro-controller; and
a circuit configured to prevent the second stage from being turned on to supply the power at the second voltage to the micro-controller, until the output of the first stage has charged the capacitor to a predetermined level sufficient to power the second stage to operate the micro-controller for a predetermined period of time even without the output of the first stage.
2. The power supply of claim 1 , wherein the first stage is a first step-down converter, and the second stage is a second step-down converter.
3. The power supply of claim 1 , wherein the first stage comprises:
a buck converter; and
at least one feedback control circuit having a switching device, wherein when the switching device is on, the output of the first stage provides the first voltage; and
when the switching device is off, the output of the first stage provides a third voltage.
4. The power supply of claim 3 , wherein the at least one switching device is selected from a group consisting of: a field effect transistor (FET), a metal-oxide-semiconductor field-effect-transistor (MOSFET), and a bipolar junction transistor.
5. The power supply of claim 3 , wherein the first stage is within a range of 10-11V to drive a MOSFET switch.
6. The power supply of claim 3 , wherein the second stage comprises a buck converter.
7. The power supply of claim 6 , wherein the second voltage is at least 2.6V.
8. A power supply, comprising:
a first stage having an input and an output, the input of the first stage to receive power from a photovoltaic panel, the output of the first stage to provide a first voltage different from the voltage received at the input of the first stage;
a switchable load connected to the output of the first stage, wherein when the switchable load is on the switchable load consumes power supplied by the first stage;
a second stage connected in parallel with the switchable load to receive power supplied by the first stage, the second stage to supply power at a second voltage to a micro-controller; and
a control circuit configured to provide a first signal to the switchable load to switch off the switchable load and a second signal to the second stage to enable output from the second stage to the micro-controller, wherein the first signal is sent prior to the second signal, and
wherein when the switchable load is off,
the switchable load does not consume power supplied by the first stage, and
the first stage provides to the second stage power that would be consumed by the switchable load if the switchable load were not off;
wherein prior to the first signal, the control circuit switches on the switchable load to emulate power consumption of the micro-controller; and the control circuit is configured to provide the first signal after the first stage is sufficient to power the switchable load.
9. The power supply of claim 8 , wherein the switchable load comprises:
a resistive device; and
a switching device connected to the resistive device and controlled by the control circuit, the switching device selected from a group consisting of: a field effect transistor (FET), a metal-oxide-semiconductor field-effect-transistor (MOSFET), and a bipolar junction transistor.
10. The power supply of claim 9 , wherein the control circuit further comprises:
a hysteresis amplifier to receive an input from the output of the first stage and to provide an output signal; and
a delay circuit to delay the output signal for the switching device.
11. The power supply of claim 8 , wherein the first stage is a first step-down converter and the second stage is a second step-down converter.
12. The power supply of claim 8 , wherein the second voltage is at least 2.6V.
13. The power supply of claim 8 , wherein the first stage comprises a buck converter and a control circuit having a switching device, wherein when the switching device is on, the output of the first stage provides the first voltage; and when the switching device is off, the output of the first stage provides a third voltage.
14. The power supply of claim 13 , wherein the at least one switching device is selected from a group consisting of: a field effect transistor (FET), a metal-oxide-semiconductor field-effect-transistor (MOSFET), and a bipolar junction transistor.
15. The power supply of claim 13 , wherein the first voltage is within the range of 10-11V; and the third voltage is 7V.
16. The power supply of claim 8 , further comprising:
a switch coupled to the output of the first stage; and
an enable circuit to turn the switch on after the power supplied at the second voltage from the second stage reaches a threshold and the control circuit is operative.
17. The power supply of claim 16 , further comprising: a capacitor coupled to the input of the second stage.
18. A method for powering a solar electric production system, comprising:
converting a voltage received from a photovoltaic panel into a first voltage different from the voltage from the photovoltaic panel;
charging a capacitor using the first voltage;
powering a power supply of a micro-controller using the capacitor and the first voltage converted from the photovoltaic panel;
preventing the micro-controller from being powered by the power supply powered by the capacitor and the first voltage, until the capacitor is charged to a predetermined level sufficient to power the micro-controller for at least a predetermined period of time without concurrent power input from the photovoltaic panel;
converting, by the power supply, the first voltage into a second voltage for the micro-controller; and
supplying the second voltage to the micro-controller after the capacitor is charged to the predetermined level.
19. The method of claim 18 , further comprising:
feeding power generated by the photovoltaic panel into a switchable load configured to emulate a load of the micro-controller, before the supplying of the second voltage to the micro-controller; and
switching off the switchable load after the first voltage is stable to support the micro-controller and before the supplying of the second voltage to the micro-controller.
20. The method of claim 19 , further comprising:
feeding the first voltage into a hysteresis amplifier having an output to prevent oscillations; and
feeding the output of the hysteresis amplifier into a delay circuit to enable the supplying of the second voltage to the micro-controller and to switch off the switchable load.
21. The power supply of claim 8 , wherein the switchable load comprises:
a resistive element connected to the first stage; and
a switch configured to allow the switchable load to drawing power from the first stage when the switch is on and to prevent the switchable load from drawing power from the first stage when the switch is off;
wherein when the switch is turned off, an amount of power that would be drawn by the switchable load from the first stage and consumed by the resistive element if the switch were turned on becomes available from the first stage to the second stage to power the micro-controller.