Description
Principle of the circuit:
12V DC voltage by V D1, all the way through R7 Luminous tube lights LED1 As a power indicator, the other way as the power supply system.
After connecting, if there is no water in the tank, both by the probeR1 level, R2Is connected to the positive power, is a high potential, IC 1 of 4Pin low throughput, the IC 1 C After the treatment, 10Pin high output, this high-level all through R4 Added VT 1 The basis, SoVT1Saturated conduction, the relay is energized to start pumping water; Other path R8 Received IC 1 of 2 Foot, due to the high level probe is also high, after the process of NAND gate, IC 1 of 3 Pin output is low, theIC1CNAND gate locked.
With the pumps to keep the water tanks, the water level in the tank gradually increased, when the low-level probe dipped in waterIC1of6Pin goes low, high output pins, but this time the NAND gate has been blocked, and so no Will affect the production, pump pumping continuous; Along with an increase in water level, when the water level probe reached a high level, IC1of1Foot and 6 Feet goes low, this change IC 1 of 4 Feet has not affected, and 3 Foot because 1 Pin goes low, the output is high, so IC 1 of 8, 9 feet are high, 10Pin goes from Low output, the de-energized relay, the pump stops pumping, but also by the low level R8 Added 2 Feet, so 3 Pin erected. Until the water level falls below the low level probe again, the previous process weight turn, and thus the switch will force the retransmission open.
