TABLEWARE WASHING MACHINE

摘要

PROBLEM TO BE SOLVED: To simplify the construction of a tableware washing machine which detects a water level and controls a water feed valve, drain device, etc. by decreasing components, to reduce cost by saving of members and spaces and to improve the reliability in production and operation by improving the degrees of freedom in design. SOLUTION: A pair of electrodes 12 and 13 are arranged at a prescribed distance from the base surface of a washing tank 11. An AC signal source 16 is connected to a primary coil 14a of a magnetic coupling circuit 14 and a first current rectifying and smoothing circuit 17 is connected thereto. A second current rectifying and smoothing circuit 18 consisting of a double voltage current rectifier circuit is connected to a secondary coil 14b of the magnetic coupling circuit 14. The output of the second current rectifying and smoothing circuit 18 is determined as a power source and the electrodes 12 and 13 are determined as input terminals. The current flowing to the resistance therebetween is determined as signal source current. The power source current is passed by a current amplifier circuit 19 for amplifying the current. The operation of the water feed valve 21 and the draining device 22 is controlled by the output of a decision circuit 20 which causes the level change of the output voltage of the first current rectifying and smoothing circuit 17 with the specified value as a boundary.