METHOD OF CONTROLLING WATER LEVEL OF HOPPER

摘要

PURPOSE:To attain a water level control method of hopper which is free from an overflow phenomenon or mixture of air into a pump with small hopper capacity, by supplying the signals of a water quantity sensor set at the upstream side of the hopper and two level sensors of the hopper and giving the linear control to a water control valve provided at the upstream side of the hopper. CONSTITUTION:When the water level is lower than the position of a level sensor 9, the inflow quantity is increased more than Q. While the inflow quantity is reduced less than the Q when the water level is higher than a level sensor 10. Both sensors 9 and 10 conduct when they are put under the water level and the currents flow to reduce the potentials of the sensor terminals. Then the sensors 9 and 10 are inconductive when they are set above the water level and no current flows. Thus the potentials of the sensor terminals are set at high levels. An interface 16 detects the change of said current or potential to change signals into a signal 1 or 0 and supplies it to a microcomputer 17. The result of the operation carried out by the computer 17 is delivered through data output terminals 18 and 19 in the form of digital codes. An interface 14 decodes these digital codes for control of a water control valve 2.