JPS54161978A - Temperature display device - Google Patents

Abstract

PURPOSE:To enable temperature of a large temperature difference to be displayed with good accuracy by making the initial value of a couter circuit settable according to a measuring temperature range and making two or more temperature changeover circuits having temperature sensors and measuring temperature display device range simultaneously changeable. CONSTITUTION:Output of an oscillation circuit 2 having an intrinsic resistance R is divided down by a frequency dividing circuit 3 and the divided outputs are converted to the specified timing signals T1 thru T3 in a timing circuit 4. Frequency dividing circuits 8, 10 are reset by the signal T1 and at the same time the minimum value of the measuring temperatures having been stored in a preset circuit 13 is read out and that value is set in a counter circuit 11. Next, either one of the outputs of temperature changeover circuits la, lb having thermistors Tha, thb is selected by the output of the circuit 4 and is supplied to the frequency dividing circuit 10 through a gate circuit 7, frequency dividing circuit 8 and gate circuit 9 only during the time of the signal T2. Further, the output supplied from the circuit 10 is counted by the counter circuit 11. When the time of the signal T2 is over, the content of the circuit 11 is latched in an output latch circuit 12 by the signal T3,from which the outputs 01 thru 0n are obtained. These are digitally displayed and the temperatures are thus measured.