Circuit for charging an electric battery by means of a photovoltaic module

1. A circuit for charging an electric battery by means of a photovoltaic module, comprising:

first and second input terminals intended to be respectively coupled to first and second terminals of the photovoltaic module;

first and second output terminals intended to be respectively coupled to first and second terminals of the battery;

a switched-mode power converter comprising first and second input terminals respectively coupled to the first and second input terminals of the charging circuit and first and second output terminals respectively coupled to the first and second output terminals of the charging circuit;

a circuit for controlling the switched-mode power converter comprising first and second power supply terminals respectively coupled to the first and second output terminals of the charging circuit;

a protection switch coupling the first output terminal of the switched-mode power converter to the first output terminal of the charging circuit; and

an overvoltage detection circuit configured to, when the voltage between the first and second output terminals of the charging circuit exceeds a threshold, send a command to turn off the protection switch and stop the switched-mode power converter for a predetermined inhibition period.

2. The charging circuit of claim 1 , wherein the overvoltage detection circuit is further configured to, at the end of the inhibition period, send a command to turn on the protection switch and restart the switched-mode power converter.

3. The charging circuit of claim 1 , wherein the control circuit is configured to control the switched-mode power converter according to the output voltage and/or current of the photovoltaic module, measured on the first and/or second input terminals of the charging circuit.

4. The charging circuit of claim 3 , wherein the control circuit is configured to automatically control the switched-mode power converter to maximize the output power of the photovoltaic module.

5. The charging circuit of claim 1 , wherein the overvoltage detection circuit comprises a comparator having its output coupled to a charging node of a timer circuit via a diode.

6. The charging circuit of claim 5 , wherein the timer circuit comprises a first capacitor and a first resistor coupled in parallel between the charging node of the timer circuit and the second output terminal of the charging circuit.

7. The charging circuit of claim 5 , wherein the overvoltage detection circuit comprises a Zener diode series-coupled with a second resistor between the first and second output terminals of the charging circuit, the comparator having a positive input terminal coupled to the junction point of the Zener diode and of the second resistor and a negative input terminal coupled to a node of application of a reference voltage.

8. The charging circuit of claim 7 , wherein the overvoltage detection circuit further comprises a resistive voltage dividing bridge comprising a third resistor in series with a fourth resistor between the first and second output terminals of the charging circuit, the node of application of the reference voltage being coupled to the junction point of the third and fourth resistors.

9. The charging circuit of claim 5 , wherein the charging node of the timer circuit is coupled to a control terminal of the protection switch and to a control terminal of the circuit for controlling the switched-mode power converter.

10. A system comprising a photovoltaic module, an electric battery, and the charging circuit of claim 1 , wherein the first and second input terminals of the charging circuit are respectively coupled to first and second terminals of the photovoltaic module, and wherein the first and second output terminals of the charging circuit are respectively coupled to first and second terminals of the battery.