Abstract: A plus width modulation (PWM) signal generator is disclosed. The PWM signal generator includes a first signal generator providing a first signal, an output terminal, a first voltage generating circuit including connected to the first voltage generating circuit for providing a first present voltage according to the first signal, and a second voltage generating circuit connected to the first signal generator for providing a second present voltage according to the first signal. The first present voltage is earlier supplied to the output terminal than the second preset voltage, and after the first preset voltage continuously is provided for a period of preset time, the first voltage generating circuit stops providing the first preset voltage.

Abstract: A control method of a smart food preparation device includes: (a) providing a user terminal device displaying a device connection key; (b) clicking the device connection key to connect a smart food preparation device and open a food preparation control page, the smart food preparation device being configured to prepare a food, and the food preparation control page having a switch control key, a mode key and a parameter key; (c) clicking the mode key and the parameter key respectively to set a food preparation mode and food preparation parameters respectively; and (d) clicking the switch control key to start the smart food preparation device to prepare the food according to the food preparation mode and the food preparation parameters.

Abstract: A plus width modulation (PWM) signal generator is disclosed. The PWM signal generator includes a first signal generator, an output terminal, a first voltage generating circuit and a second voltage generating circuit. The first signal generator provides a first signal. The first voltage generating circuit includes a voltage division circuit and is connected to the first signal generator and the output terminal, and provides a first preset voltage to the output terminal according to the first signal and a voltage division circuit. The second voltage generating circuit is connected to the first signal generator and the output terminal, and provides a second preset voltage to the output terminal according to the first signal. The first present voltage is earlier supplied to the output terminal than the second preset voltage, and after the first preset voltage continues to provide the preset time, the first preset voltage generating circuit stops providing the first preset voltage.