| 摘要 |
PURPOSE:To enable sure dehydration operation of good efficiency to be accomplished by providing a light emitting element, a photo detector and a prism which is positioned between these and lets the light emitted from the light emitting element be refracted and be arrived at the photo detector in the position exposed to denydration water. CONSTITUTION:When the water dehydrated from the objecft to be dehydrated accumulates temporarily in a water receiving tank 2 and a prism 41 is submerged in the water, then the light emitted from a light emitting diode 32 transmits through the prism 41 without being refracted thereby, failing to arrive at a transistor 23, hence the output of the transistor 23 decreases sharply. The water in the water receiving tank 2 is quickly discharged thereafter, but while the water drops of the dehydration water sprinkle on the prism, the light irregularly reflects at the portions of the prism where the water drops have deposited, thus failing to arrive at the transistor 23. When the dehydraton water decreases in due course of time, the output of the transistor 23 rises and when it reaches the preset value of dehydration completion, the rotary tank 3 stops as the motor 4 stops running, thus the dehydration operation is completed. |
