Thermostatic control device of electric water heater

The utility model discloses a thermostatic control device for electric water heaters, which comprises an influent/effluent temperature sensor, an influent flow sensor, a microprocessor, a pulse width modulator for receiving microprocessor signals, as well as a power control component. The signals of the influent/effluent temperature sensor and the influent flow sensor are input to the microprocessor; the heating power of the power control component is controlled by the output signals of the pulse width modulator; the microprocessor carries out operation processing to influent temperature, influent flow and effluent temperature and then outputs signals to the pulse width modulator; and the pulse width modulator outputs pulses with a certain duty ratio to control the heating power of the power control component, so as to precisely control the effluent temperature of an electric water heater and realize the constant of the effluent temperature of the electric water heater. Meanwhile, due to the precise operation processing of the microprocessor for acquired data, as well as the control of the pulse width modulator on the heating power, the effluent temperature of the electric water heater can not be too cold or too hot, which saves electric energy as well, namely the corresponding electric energy is provided according to the needed heat of effluent water.