Household flower pot automatic watering device

As we all know, most of the balconies in homes usually have some flowers and plants planted, which can be watered on time. However, if you need to take care of these flowers and plants when you are away on business or traveling, especially for a long time, you always have to trouble your neighbors or relatives, which is very inconvenient. For this reason, the author has made a device suitable for the above situation, which can automatically water the flowers and plants when the owner is not at home - a household flower pot automatic sprinkler. ．

The circuit working principle diagram is shown in Figure 1. The circuit power supply converts the 220v city power into 12v AC power through a transformer, and then rectifies through four diodes D1~D4, and then supplies power after filtering into DC by electrolytic capacitor C. The transistor V1, resistor R, and DC relay coil in the circuit form a basic control circuit. As long as DC power is generated, the base of the transistor V1 obtains the base bias current through the resistor R, so that the collector and emitter of the transistor are saturated and turned on, the DC relay coil K is energized, the DC relay normally open switch K-1 is closed, the solenoid valve coil is energized, and water flows into the flower pot through the water pipe. When the water in the flower pot reaches a certain amount, that is, the probe connected to the connector is short-circuited due to water, the base current of the transistor V1 is short-circuited, the transistor enters the cut-off state, the DC relay coil is powered off, the DC relay normally open switch K-1 is disconnected, and the water inlet electromagnetic valve is powered off to stop the water supply to the flower pot. As long as the water in the flower pot evaporates, the transistor enters the saturated state again due to the probe disconnection, and the cycle continues to achieve the purpose of automatic watering.

Selection of circuit components: The power switch should be the switch on the panel with switch socket, the AC power transformer can be a 10w, 220V/12V transformer, the diodes D1~D5 can be IN4001, the capacitor C can be a 100μF/50V electrolytic capacitor, the resistor R is 20kΩ, 1/8W, the transistor is 9013, the DC relay can be a 12V ordinary DC relay, the water inlet solenoid valve can be a washing machine water inlet solenoid valve, and the probe can be replaced by 1mm2 copper wire. The installation of the automatic sprinkler is shown in Figure 2.

Automatic sprinkler installation precautions:

1. The probe should be inserted into the bottom of the flower pot.

2. When using multiple flower pots, the probes can be connected in series, and a soft rubber hose can be used as the water inlet pipe. A small hole can be opened at the position of the corresponding flower pot to ensure that water can flow into the flower pot when there is water flowing through.

3. The water inlet pipe and related wires must be properly fixed.

4. Because water is usually poured on the balcony, the circuit board must be waterproofed.