| 摘要 |
<p>PURPOSE:To enable to detect temperatures with high reliability to the dispersion of resistance value of thermister, by selecting the resistance value of the bridge circuit so that the detected voltage of thermister can linearly be changed to the change in the set voltage. CONSTITUTION:The resistance value Rth of the thermister 3 shows a given characteristic according to the temperature T of the detection end, and when the value of the fixed resistor 4 is suitably selected in the bridge circuit 2 the detection voltage eT is obtained to the temperature T. Taking the detection range of the temperature T is taken as T1-T2, the voltage eT is given almost as a straight line, and the fixed resistors 5-7 are selected so that the two voltages e1, e2 of the junction between the two end terminals of the variable resistor 8 and the fixed resistor 6 can be equal to the value of detection voltage eT at temperatures T1, T2. As a result, when the resistor 8 is changed from minimum to maximum, the set voltage ed changes in straight line from the voltage e1 to e2, and the temperature T when the voltages ed equals to eT is almost linearly changes with the change in the voltage ed.</p> |
