Power supply module and soft start method

1. A power supply module, comprising:

at least two Direct Current (DC) buses;

a capacitor coupled between the at least two DC buses;

a current limiting circuit including at least one current limiting resistor, the current limiting circuit coupled to at least one of the DC buses;

a connection terminal having a first detection joint and a second detection joint; and

an input detection circuit coupled to at least one of the first detection joint and the second detection joint and configured to output a first notification signal to a trigger drive circuit when it is determined, by detecting a short-circuit between the first detection joint and the second detection joint, that the power supply module begins to receive a power supply signal;

the trigger drive circuit configured to wait for a predetermined duration without sending a drive signal to the current limiting circuit when the first notification signal sent from the input detection circuit is received by the trigger drive circuit, and to send the drive signal to the current limiting circuit when the predetermined duration elapses, the predetermined duration determined according to values of the capacitor coupled between the at least two DC buses, and the current limiting resistor of the current limiting circuit; and

the current limiting circuit configured to limit a current on at least one of the DC buses of the power supply module when the drive signal is not received by the current limiting circuit, and not to limit the current on said at least one of the DC buses when the drive signal is received by the current limiting circuit.

2. The power supply module according to claim 1 , wherein:

the input detection circuit is further configured to output a second notification signal to the trigger drive circuit when it is determined that the power supply module no longer receives the power supply signal; and

the trigger drive circuit is further configured not to send the drive signal to the current limiting circuit when the second notification signal sent from the input detection circuit is received by the trigger drive circuit.

3. The power supply module according to claim 2 , wherein: when the first detection joint and the second detection joint are short-circuited by a short-circuit joint in a connection terminal of a power supply system providing the power supply signal to the power supply module, joints other than the first detection joint and the second detection joint in the connection terminal of the power supply module are connected to corresponding joints in the connection terminal of the power supply system respectively; and

when the first detection joint and the second detection joint are short-circuited by the short-circuit joint in the connection terminal of the power supply system, the input detection circuit outputs the first notification signal, and when the first detection joint and the second detection joint are disconnected, the input detection circuit outputs the second notification signal.

4. The power supply module according to claim 3 , wherein the length of each of the first detection joint and the second detection joint in the connection terminal of the power supply module is less than the lengths of other joints in the connection terminal of the power supply module.

5. The power supply module according to claim 3 , wherein the input detection circuit comprises: a first resistor, a second resistor, a second capacitor and an optical coupler;

one terminal of the first resistor receives a first voltage signal, the other terminal of the first resistor is connected to a first electrode of a light-emitting diode in the optical coupler, and a second electrode of the light-emitting diode in the optical coupler is connected to the second detection joint; a collector of a phototransistor in the optical coupler is connected to one terminal of the second resistor, the other terminal of the second resistor receives a high-level signal, and an emitter of the phototransistor in the optical coupler receives a first ground signal; one terminal of the second capacitor is connected to the collector of the phototransistor in the optical coupler and to the trigger drive circuit respectively, and the other terminal of the second capacitor is connected to the emitter of the phototransistor in the optical coupler and to the trigger drive circuit respectively; the first detection joint receives a second ground signal; and

the optical coupler is configured to output a low-level signal to the trigger drive circuit when the first detection joint and the second detection joint are short-circuited by the short-circuit joint in the power supply system and thereby the light-emitting diode emits light and the conducting between the collector of the phototransistor and the emitter of the phototransistor is formed, and to output a high-level signal to the trigger drive circuit when the first detection joint and the second detection joint are disconnected and thereby the light-emitting diode does not emit light and the conducting between the collector of the phototransistor and the emitter of the phototransistor is broken.

6. The power supply module according to claim 3 , wherein the input detection circuit comprises: a first resistor, a second resistor, a second capacitor and a transistor;

one terminal of the first resistor receives a voltage signal, and the other terminal of the first resistor is connected to the second detection joint; a gate electrode of the transistor is connected to the first detection joint, a first electrode of the transistor is connected to one terminal of the second resistor, the other terminal of the second resistor receives a high-level signal, a second electrode of the transistor receives a ground signal, one terminal of the second capacitor is connected to the first electrode of the transistor and to the trigger drive circuit respectively, and the other terminal of the second capacitor is connected to a second electrode of the transistor and to the trigger drive circuit respectively; and

the transistor is configured to output a low-level signal to the trigger drive circuit when the first detection joint and the second detection joint are short-circuited by the short-circuit joint in the power supply system and thereby the conducting between the first electrode of the transistor and the second electrode of the transistor is formed, and to output a high-level signal to the trigger drive circuit when the first detection joint and the second detection joint are disconnected and thereby the conducting between the first electrode of the transistor and the second electrode of the transistor is broken.

7. The power supply module according to claim 3 , wherein the input detection circuit comprises: a first resistor, a second resistor, a second capacitor and a relay;

one terminal of the first resistor receives a voltage signal, the other terminal of the first resistor is connected to one terminal of a coil in the relay, and the other terminal of the coil in the relay is connected to the second detection joint; one terminal of a normally open contact in the relay is connected to one terminal of the second resistor, the other terminal of the relay receives a high-level signal, and the other terminal of the normally open contact in the relay receives a first ground signal; one terminal of the second capacitor is connected to the one terminal of the normally open contact in the relay and to the trigger drive circuit respectively, and the other terminal of the second capacitor is connected to the other terminal of the normally open contact in the relay and to the trigger drive circuit respectively; the first detection joint receives a second ground signal; and

the relay is configured to output a low-level signal to the trigger drive circuit when the first detection joint and the second detection joint are short-circuited by the short-circuit joint in the power supply system and thereby the normally open contact in the relay is closed, and to output a high-level signal to the trigger drive circuit when the first detection joint and the second detection joint are disconnected and thereby the normally open contact in the relay is open.

8. The power supply module according to claim 1 , wherein the current limiting circuit is connected in at least one of the DC buses of the power supply module, or the current limiting circuit is connected in series with the capacitor of the power supply module and then is connected between the two DC buses of the power supply module.

9. A soft start method, comprising:

outputting, by an input detection circuit, a first notification signal to a trigger drive circuit when it is determined, by detecting a short-circuit between a first detection joint and a second detection joint of a connection terminal of a power supply module, that the power supply module begins to receive a power supply signal;

waiting for a predetermined duration without sending a drive signal to a current limiting circuit by the trigger drive circuit when the first notification signal sent from the input detection circuit is received by the trigger drive circuit, and sending, by the trigger drive circuit, the drive signal to the current limiting circuit when the predetermined duration elapses, the predetermined duration determined according to values of a current limiting resistor of the current limiting circuit and a capacitor coupled between two DC buses of the power supply module; and

limiting, by the current limiting circuit, a current on at least one of the two DC buses of the power supply module when the drive signal is not received by the current limiting circuit, and not limiting, by the current limiting circuit, the current on said at least one of the two DC buses when the drive signal is received by the current limiting circuit.

10. The method according to claim 9 , further comprising:

outputting, by the input detection circuit, a second notification signal to the trigger drive circuit when it is determined that the power supply module no longer receives the power supply signal; and

not sending, by the trigger drive circuit, the drive signal to the current limiting circuit when the second notification signal sent from the input detection circuit is received by the trigger drive circuit.

11. The method according to claim 9 , wherein the outputting, by the input detection circuit, the first notification signal to the trigger drive circuit comprises:

outputting, by the input detection circuit, the first notification signal when the first detection joint and the second detection joint in the connection terminal of the power supply module are short-circuited by a short-circuit joint in a power supply system providing the power supply signal to the power supply module.

12. The method according to claim 11 , wherein the outputting, by the input detection circuit, the second notification signal to the trigger drive circuit when it is determined that the power supply module no longer receives the power supply signal comprises:

outputting, by the input detection circuit, the second notification signal when the first detection joint and the second detection joint are disconnected.

13. The method according to claim 11 , wherein the first notification signal is a low-level signal.

14. The method according to claim 12 , wherein the second notification signal is a high-level signal.

15. The power supply module of claim 1 , wherein the trigger drive circuit comprises a digital signal processor (DSP) configured to monitor whether the power supply signal has been received and implement a delay function corresponding to the predetermined duration.