Intelligent energy-saving water dispenser design circuit diagram

Single chip microcomputer STM32L151CCU6

One-piece inductor

After the ordinary household water dispenser turns on the heating power, no matter whether there is anyone in the room, or whether it is heated or kept in the day or night, the pure water in the heating tank is heated repeatedly for a long time, which is not only unhealthy but also quite Fees are charged. The author has modified the ordinary household water dispenser for the above shortcomings. The microwave induction principle is used to enable the drinking fountain machine to automatically detect the presence or absence of personnel activities in the room. At the same time, it is judged whether the personnel in the room are only briefly passed, and then the heating function is automatically controlled so that the water dispenser has Intelligent and power saving features.

Working principle: The newly added components in the figure have a typical capacitor step-down circuit composed of Cl, C2, Rl, DW, D, which provides a stable llV DC voltage to the TX982 and 555 time base circuits. The TX982 is a microwave induction controller. The microprocessor contains a microwave Doppler effect to establish a micro electric field in a certain space. When a person or a moving object enters an electric field, it will reflect the echo, and after the electronic line is mixed, the pole is detected. A weak frequency shift signal, which is intelligently processed to output a control signal. The effective monitoring radius of the TX982 is 1~7 meters. The reason why the pyroelectric sensor is not used here is mainly because the modification is convenient, and the pyroelectric sensor is particularly sensitive to the heat source and is easy to malfunction. The microwave induction controller can be detected by installing it behind the plastic panel of the water dispenser without damaging the appearance of the water dispenser. The output of the TX982 uses an open-collector output. When the microwave circuit detects that someone is moving within the monitoring range, the internal transistor is turned on for 10 seconds to discharge the charge on C3. The 555 circuit constitutes a one-shot delay circuit. When the second pin is lower than 1/3 of the power supply voltage, the third pin outputs a high level, the relay pulls in, the Kl turns on the heater for heating, and the delay time composed of R2 and C3 For 3 minutes, the delay time is set to be relatively short. If the personnel only passes briefly, the water dispenser will automatically stop after heating for 3 minutes. If there is someone in the room, the TX982 will trigger the one-shot circuit multiple times within the delay time. Work, the water dispenser will continue to heat until the set temperature is reached.

If you want to further improve the energy-saving effect, you need to make some small modifications to the heating tank of the water dispenser. The insulation measures of most water dispensers are very simple. Only two pre-formed foams are used to enclose the heating tank, so the heat dissipation is very fast. It is best to use the polyurethane material (generally manufactured by the manufacturer of solar water heaters) to carry out on-site foaming filling around the heating tank. This treatment can make there is no gap between the thermal insulation material section and the heating tank, and reducing the air flow can greatly improve the heat preservation effect. .