how to make automatic water pump

Advertisement
Similarly, the upper-limit probe ‘B’ is hooked up to the base of transistor T2 (BC547), the collector of that’s related to the 12V power supply and the emitter is connected to pins 1 and a pair of of NAND gate N1 and ground via resistor R3. The output pin four of NAND gate N2 is hooked up to pin 12 of NAND gate N3. The output of N3 is attached to enter pin 6 of N2 and the base of transistor T3 through resistor R4. Relay RL2 linked to the emitter of transistor T3 is used to force the motor.

Circuit operation
If the tank is stuffed beneath probe A, transistors T1 and T2 do not conduct and the output of N3 goes high. This high output energises relay RL2 to force the motor and it starts offevolved pumping water into the tank.

When the tank is stuffed above probe A but under probe B, water inside the tank presents base voltage to force transistor T1 and relay RL1 energises to make pin 13 of gate N3 excessive. However, water in the tank does now not offer base voltage to transistor T2, so it does now not behavior and the good judgment built around NAND gates N1 and N2 outputs low to pin 12 of gate N3. The internet effect is that the output of N3 stays high and the motor continues pumping water into the tank.

When the tank is stuffed up to probe B level, water in the tank nonetheless affords base voltage to transistor T1 and relay RL1 energises to make pin 13 of gate N3 excessive. At the same time, water inside the tank additionally offers base voltage to force transistor T2 and the common sense constructed around NAND gates N1 and N2 outputs high to pin 12 of gate N3. The net effect is that the output at pin 11 of N3 goes low and the motor stops pumping water into the tank.

When water degree falls beneath probe B however above probe A, water within the tank nevertheless presents base voltage to transistor T1 and relay RL1 stays energised to make pin 13 of gate N3 excessive. However, transistor T2 doesn’t behavior and the good judgment constructed round NAND gates N1 and N2 outputs high to pin 12 of N3. As a end result, the output of N3 remains low and motor remains stopped.

When water degree falls beneath probe A, both transistors T1 and T2 do not conduct. NAND gate N3 offers a high output to force relay RL2 and the motor restarts pumping water into the tank.

2 shows the indicator/tracking circuit. It consists of 5 LEDs, which glow to suggest the level of water within the overhead tank. Since 12V strength supply is given to water at the bottom of the tank, transistors T3 through T7 get base voltage and behavior to mild up the LEDs (LED5 down through LED1).

When water in the tank reaches the minimal at stage C, transistor T7 conducts and LED1 glows. When water level rises to at least one-fourth of the tank, transistor T6 conducts and LED1 and LED2 glow. When water stage rises to half of of the tank, transistor T5 conducts and LED1, LED2 and LED3 glow. When water level rises to 3-fourth of the tank, transistor T4 conducts and LED1 through LED4 glow. When the tank is full, transistor T3 conducts and all of the 5 LEDs glow. So, from sparkling of LEDs, it is easy to know water degree in the tank (see the table). The LEDs can be installed anywhere for smooth tracking.

Note: The user can alter the level to which water ought to be filled in the tank via adjusting the heights of probes A and B. The stand and adjusting screws ought to be insulated to keep away from shorting.