| 摘要 |
PURPOSE:To hold the current state of operation by a method wherein the input terminal of an AND gate is forcibly brought into a LOW level and following inputs to the AND gate are refused. CONSTITUTION:When a lock operation switch 4 is in an OFF state, voltages 'H' of a High level are continuously inputted to the input terminals A of AND gates 5 and 6. When, with this state, a rapid freezing operation switch 2 and deodorizing operation switch 3 are brought into an ON-state, the voltage 'H' is outputted in a single shot-like manner. However, when, during rapid freezing or deodorizing operation, the lock operation switch 4 is brought into an ON- state, a voltage at the terminals A of the AND gates 5 and 6 is brought into a Low level, whereby even when the operation switches 2 and 3 are operated to bring a terminal B into an 'H' state, a terminal X is not brought into an 'H' state. Namely, an operation state selected once is prevented from being imprudently canceled by other selector. |
