No tower as shown pressurized water supply equipment for the level control circuit. The control circuit consists of capacitor step-down circuit, electric contact pressure gauge, trigger circuit 555, SCR control circuit. One buck rectifier circuit for the entire control circuit to provide DC voltage.
Electric contact pressure gauge on P, when the water inside the water, the internal pressure is low, the dynamic contact table “l” minimum contacts with the “3” closed, so that IC (555) pin is low, The corresponding set 555, 3 feet high so that the output of SCR trigger the SCR conduction, CJ pull, inside the water pump to draw water to the D, pressure meter, pressure rise. When the moving contact “1” up to and “3” out, and limit contact with the “2” joints, the 555 due to occur reset pin is high, the SCR off, pump D to stop work due to no power . Since then, the water, the water level dropped, the table pressure falls, the moving contact “l” and limit contact with the “3” joint, so that 555 set, SCR conduction. Pump pumping. So the cycle. To achieve the level of water supply device control action.
CJ circuit using CJ-40A, AC contactor, optional bi-directional SCR 3A/400V can directly drive its work.
Use this control circuit can realize the automatic water level control action device. But can also avoid the electrical contacts of the contacts is singeing or sintering phenomenon, extending its life.