Abstract: An improved temperature control device which is arranged to generate comparative output ratio signals linearly varying successively from a small value to a large value in a manner as in time series in correspondence to sampling period, at each proportional period including several periods of the sampling period, and also to successively compare the output ratio and the comparative output ratio at each of the sampling period, thereby to turn on an output control section at a subsequent sampling period when the sampling output ratio is larger than the comparative output ratio.

Abstract: A PID controlling meter is provided with unit for displaying an amount of operation representing the sum total of the bias constant and the operation result of three terms, i.e., a proportional term, an integrating term and differentiating term each of which is a function of deviation. The meter also has a constant setting unit for setting displayed amount of operation as a control parameter; unit for displaying set values of the constant setting a unit; a unit for reading the set values of the constant setting unit when a power source is closed; and a unit for determining bias constant when the power source is closed on the basis of the constant set values read by the reading unit.

Abstract: An improved temperature control device which is so arranged that, by obtaining an average value of digital output amount of an A/D converter, if variation of the above digital output amount average value at each sampling is within predetermined dead zone data, it is regard that there is no change, while on the other hand, if the above variation is larger than the dead zone data, control is effected on the assumption that variation has taken place by the amount obtained by removing the dead zone data from the amount of the variation.