| 摘要 |
A current zero-crossing detection circuit and method, and load voltage detection circuit and method, the current zero-crossing detection circuit comprising: a load power supply circuit (14), a voltage dividing resistor (16), a switch (15) and a zero-crossing detection circuit (19); the load power supply circuit (14) comprises a load (11), a diode (13) and an inductor (12); one end of the load power supply circuit (14) is connected to a working voltage input end, and other ends of the load power supply circuit (14) are connected to a first end of the switch (15) and a first end of the voltage dividing resistor (16); a second end of the voltage dividing resistor (16) and a second end of the switch (15) are grounded; by controlling the load voltage via the switch (15), a voltage dividing end of the voltage dividing resistor (16) is connected to a signal input end of the zero-crossing detection circuit (19); and the on-time of the diode (13) can be obtained by determining, via the zero-crossing detection circuit (19), whether the current of the diode (13) crosses a zero point. The load voltage detection circuit can acquire the load voltage by using the on-time of the diode (13) and the on-time of the switch (15). The circuit has a simple structure, a high detection efficiency and a low cost. |
