Abstract: A sprayer includes: a container; a passage including a transparent window, a first opening, a second opening and a resonator, wherein when liquid in the container is passed through the resonator via the first opening, the liquid is emitted as a gas via the second opening; and a removable detection unit disposed outside of the passage. The removable detection unit includes: a light source for illuminating the gas in the passage; an optical sensor disposed to detect a parameter of light reflected by the gas; and a processor coupled to the optical sensor for stopping the resonator from generating the gas when the parameter is below a threshold. The passage further includes a cavity disposed on a bottom surface of the passage in front of the optical sensor, wherein when the gas in the passage contacts the bottom surface, resultant water vapour will enter the cavity.

Abstract: A multi-phase brushless DC motor driving circuit includes a driving-stage circuit, a PWM generator, a control circuit and a plurality of current detection circuits. The driving-stage circuit includes a plurality of sub-driving circuits each having a high-side transistor and a low-side transistor. The current detection circuits detect the current at a node between the high-side transistor and the low-side transistor of the corresponding sub-driving circuit, and then generate a current detection signal. According to the current detection signals, the control circuit controls the PWM generator to generate a plurality of PWM signals for controlling the conducting and cutting off of the high-side transistor and the low-side transistor of each sub-driving circuit, and to provide a driving current to drive a multi-phase brushless DC motor.

Abstract: A multi-phase brushless DC motor driving circuit includes a driving-stage circuit, a PWM generator, a control circuit and a plurality of current detection circuits. The driving-stage circuit includes a plurality of sub-driving circuits each having a high-side transistor and a low-side transistor. The current detection circuits detect the current at a node between the high-side transistor and the low-side transistor of the corresponding sub-driving circuit, and then generate a current detection signal. According to the current detection signals, the control circuit controls the PWM generator to generate a plurality of PWM signals for controlling the conducting and cutting off of the high-side transistor and the low-side transistor of each sub-driving circuit, and to provide a driving current to drive a multi-phase brushless DC motor.