Zero-crossing detection device and method thereof and no-neutral switch

1. A zero-crossing detection device for a no-neutral switch, wherein the no-neutral switch comprises a switch element, the switch element has a first end connected to a power supply and a second end connected to a load, wherein the zero-crossing detection device comprises:

a computing module;

a sampling module configured to sample a first signal of the first end of the switch element and a second signal of the second end of the switch element; and

a comparison module configured to compare a deviation of the first signal and the second signal with a preset threshold and to send a triggering signal to the computing module when the deviation exceeds the preset threshold;

wherein the computing module is configured to compute a zero-crossing point of the power supply according to time of the triggering signal and time delay of the triggering signal relative to the zero-crossing point according to frequency of the power supply and the preset threshold.

2. The detection device of claim 1 , wherein the computing module is further configured to compute the frequency of the power supply according to an interval between at least two adjacent triggering signals.

3. The detection device of claim 1 , wherein the computing module is further configured to set the frequency of the power supply to a default value.

4. The detection device of claim 1 , wherein the comparison module comprises an operational amplifier configured to compare the deviation of the first signal and the second signal with the preset threshold.

5. The detection device of claim 1 , wherein the first signal and the second signal are voltage signals.

6. The detection device of claim 1 , wherein the computing module is further configured to have wireless communication function.

7. The detection device of claim 1 , wherein the switch element is configured to adjust power provided to the load from the power supply according to the zero-crossing point provided by the zero-crossing detection device.

8. The detection device of claim 1 , further comprising a power converter configured to convert a voltage from the power supply to a power voltage provided to the computing module of the zero-crossing detection device.

9. The detection device of claim 1 , wherein the switch element is a bidirectional thyristor.

10. A no-neutral switch, comprising:

a zero-crossing detection device; and

a switch element connected with the zero-crossing detection device, having a first end connected to a power supply and a second end connected to a load, configured to adjust power provided to the load from the power supply according to the zero-crossing point provided by the zero-crossing detection device;

wherein the zero-crossing detection device comprises:

a computing module;

a sampling module configured to sample a first signal of the first end of the switch element and a second signal of the second end of the switch element; and

a comparison module configured to compare a deviation of the first signal and the second signal with a preset threshold and to send a triggering signal to the computing module when the deviation exceeds the preset threshold;

wherein the computing module is configured to compute a zero-crossing point of the power supply according to time of the triggering signal and time delay of the triggering signal relative to the zero-crossing point according to frequency of the power supply and the preset threshold.

11. The no-neutral switch of claim 10 , further comprising a power converter configured to convert a voltage from the power supply to a power voltage provided to the computing module of the zero-crossing detection device.

12. The no-neutral switch of claim 10 , wherein the switch element is a bidirectional thyristor.

13. A method of detecting a zero-crossing point of a power supply for a no-neutral switch, wherein the no-neutral switch comprises a switch element, the switch element has a first end connected to the power supply and a second end connected to a load, wherein the method comprises:

sampling a first signal of the first end of the switch element and a second signal of the second end of the switch element;

comparing a deviation of the first signal and the second signal with a preset threshold that comprises when the deviation exceeds the preset threshold, sending a triggering signal; and

computing the zero-crossing point of the power supply according to time of the triggering signal and time delay of the triggering signal relative to the zero-crossing point and computing the time delay according to frequency of the power supply and the preset threshold.

14. The method of claim 13 , wherein computing the zero-crossing point of the power supply further comprises: computing the frequency of the power supply according to an interval between at least two adjacent triggering signals.

15. The method of claim 13 , wherein computing the zero-crossing point of the power supply further comprises: setting the frequency of the power supply to a default value.

16. A storage medium, wherein the storage medium comprises a stored program, wherein a device where the storage medium is positioned is controlled to implement the method of claim 13 when the program runs.

17. A processor, wherein the processor is applied to execute a program, wherein the method of claim 13 is implemented when the program is executed.