| 摘要 |
PURPOSE:To automatically check the normal operation by switching a temperature sensing resistor of an oscillator to a reference resistor for checking normal operation during a fixed normal operation checking time. CONSTITUTION:While output is coming from a timer 14, a push switch is kept on for a fixed time during which either a reference resistor R or a reference resistor RF for normal operation checking is selected with a logic of an OR circuits 22 and 23 and an inverter 18. In other words, the resistor R or the resistor RF is selected depending on whether an FF1 is set or reset and a temperature value conversion data corresponding to the RF is latched into a latch circuit 3. When a correct temperature corresponding to the resistor RF which is stored beforehand is equal to a value indicated 13 during the operation of the timer 14, one can ascertains that is operates normally. When the output of the timer 14 goes to L, a normal temperature measurement starts. |
