Abstract: A heating control circuit and a ventilator are provided. The heating control circuit includes a control device and a switching device, an input end of the control device being connected to an alternating-current power source, an output end thereof being connected to a control end of the switching device, and an output end of the switching device is connected to a heating member; and the control device is configured to generate, according to different output voltages of the alternating-current power source, a driving signal for controlling a duty ratio of the switch device to adaptively change, so that the power output from the switching device to the heating member is constant.

Abstract: A humidification control system comprises a ventilation therapy apparatus main body, a respiratory humidifier, a heating pipeline and a nasal oxygen cannula, wherein the ventilation therapy apparatus main body comprises a fan and a first controller, the respiratory humidifier comprises a water tank, a heating plate, a water tank air inlet temperature sensor and a heating plate temperature sensor, an air outlet of the fan is connected to an air inlet of the water tank; an air outlet of the water tank is connected to an air inlet of the heating pipeline; an air outlet of the water tank is connected to an input port of the nasal oxygen cannula; the heating pipeline comprises a heating pipeline air inlet temperature sensor and a heating pipeline heating control module; and the first controller makes the relative humidity of the current first mixed airflow.

Abstract: A charger for a motorized tool includes a filter circuit, a rectifier circuit, a pulse width modulation (PWN) circuit, a transformer circuit, and a sensing circuit. Thus, the sensing circuit captures partial of the output voltage to compare with a reference voltage to obtain an error signal between the output voltage and the reference voltage and feeds back the error signal to the PWN circuit to change the pulse width of the PWN circuit so as to regulate the duty cycle of the power switch, so that the output voltage and current are adjusted according to the feedback error signal so as to charge the battery exactly and stably.

Abstract: A charger for a motorized tool includes a filter circuit, a rectifier circuit, a pulse width modulation (PWN) circuit, a transformer circuit, and a sensing circuit. Thus, the sensing circuit captures partial of the output voltage to compare with a reference voltage to obtain an error signal between the output voltage and the reference voltage and feeds back the error signal to the PWN circuit to change the pulse width of the PWN circuit so as to regulate the duty cycle of the power switch, so that the output voltage and current are adjusted according to the feedback error signal so as to charge the battery exactly and stably.