An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.

An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.

A circuit and a method for detecting a current zero-crossing point, and a circuit and method for detecting a load voltage are disclosed. The circuit for detecting current zero-crossing point includes: a load power supply circuit, a voltage-dividing resistor, a transistor switch, a zero-crossing detection circuit; the load power supply circuit includes: a load, a diode, and a transformer; one end of a primary winding of the transformer is connected with the operating voltage input terminal, the other end of the primary winding of the transformer is connected with a first end of the transistor switch and a first end of the voltage-dividing resistor, a second end of the voltage-dividing resistor and a second end of the transistor switch are connected with the ground, the load voltage is controlled by the transistor switch.

A circuit and a method for detecting a current zero-crossing point, and a circuit and method for detecting a load voltage are disclosed. The circuit for detecting current zero-crossing point includes: a load power supply circuit, a voltage-dividing resistor, a transistor switch, a zero-crossing detection circuit; the load power supply circuit includes: a load, a diode, and a transformer; one end of a primary winding of the transformer is connected with the operating voltage input terminal, the other end of the primary winding of the transformer is connected with a first end of the transistor switch and a first end of the voltage-dividing resistor, a second end of the voltage-dividing resistor and a second end of the transistor switch are connected with the ground, the load voltage is controlled by the transistor switch.

An apparatus includes a first half-cell, a second half cell and a multiplexer. The first half-cell may comprise a first input stage configured to present a first input signal to a first auto-zero stage. The second half-cell may comprise a second input stage configured to present a second input signal to a second auto-zero stage. The multiplexer may receive a first output from the first auto-zero stage, receive a second output from the second auto-zero stage and present one of the first output and the second output. The first half-cell and the second half-cell may implement a capacitive coupling. The capacitive coupling may provide a rail-to-rail common-mode input range. The first half-cell and the second half-cell may prevent a mismatch between data signals and clock signals. The first half-cell and the second half-cell may each be configured to implement a calibration when idle.

An apparatus includes a first half-cell, a second half cell and a multiplexer. The first half-cell may comprise a first input stage configured to present a first input signal to a first auto-zero stage. The second half-cell may comprise a second input stage configured to present a second input signal to a second auto-zero stage. The multiplexer may receive a first output from the first auto-zero stage, receive a second output from the second auto-zero stage and present one of the first output and the second output. The first half-cell and the second half-cell may implement a capacitive coupling. The capacitive coupling may provide a rail-to-rail common-mode input range. The first half-cell and the second half-cell may prevent a mismatch between data signals and clock signals. The first half-cell and the second half-cell may each be configured to implement a calibration when idle.

A zero-crossing detection circuit includes a zero-crossing detection unit arranged to compare a first monitoring target signal and a second monitoring target signal respectively input through diodes from a first node and a second node between which an AC signal is applied, so as to generate a first comparison signal, and a logic unit arranged to estimate a zero cross of the AC signal from the first comparison signal so as to generate a zero-crossing detection signal. The zero-crossing detection circuit preferably includes a monitoring unit arranged to adjust the first monitoring target signal and the second monitoring target signal to be suitable for input to the zero-crossing detection unit. The logic unit preferably counts a period of the first comparison signal and estimates a zero cross of the AC signal using a count value thereof.

A zero-crossing detection circuit includes a zero-crossing detection unit arranged to compare a first monitoring target signal and a second monitoring target signal respectively input through diodes from a first node and a second node between which an AC signal is applied, so as to generate a first comparison signal, and a logic unit arranged to estimate a zero cross of the AC signal from the first comparison signal so as to generate a zero-crossing detection signal. The zero-crossing detection circuit preferably includes a monitoring unit arranged to adjust the first monitoring target signal and the second monitoring target signal to be suitable for input to the zero-crossing detection unit. The logic unit preferably counts a period of the first comparison signal and estimates a zero cross of the AC signal using a count value thereof.

An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.

An electric working machine according to one aspect of the present disclosure comprises a motor, a rectifier circuit, a capacitor, a series switching element, a resistive element, a drive circuit, a peak voltage value acquirer, and a controller. The capacitor smooths power rectified by the rectifier circuit. The series switching element is coupled in series with the capacitor. The resistive element is coupled in parallel with the series switching element. The controller brings the series switching element into conduction in a case where AC power is inputted to the rectifier circuit and where a specified conducting condition based on a peak voltage value acquired by the peak voltage value acquirer is satisfied.