At this thermometer circuit, the sensor (S8100) or diode (1S1588) is used as the thermo sensor. When using the IC thermo sensor, the thermometry to +100°C from -40°C is possible. Also, when using the diode, the measurement to +150°C from -20°C is possible. Both sensors are contained in the kit.
This time, the thermometer circuit used the diode as the thermo sensor to measure more than +100°C. ICL7136 is used for the thermometer and is measuring the change of the forward direction minute voltages of the diode by the temperature. The 3-1/2 digits liquid crystal display (SP521PR) is used for the display. The most significant digit can display only "1".
The consumption electric power of ICL7136 is very small and it is possible to operate about 3 months continuously with the 9-V cell.
Liquid crystal display (LCD) SP521PR Pinning
Specification of LCD SP521PR .
4 digits display
The letter height : 12.7 mm
The maximum applied voltage : 10 V
The operating temperature : -10 to 55°C
4 digits display
The letter height : 12.7 mm
The maximum applied voltage : 10 V
The operating temperature : -10 to 55°C
Note: When using the 5-V power supply, the resistor as much as 10K-ohm must be put in series to prevent from big electric current's flowing in case of the short circuit.