This circuit in below is show the simple form of the thermometer circuit. The circuit is based on LM335 as sensing the temperature. This is the figure of the circuit.
The circuit consists of two parts: The LM335 and its adjustment. The output of the LM335 is 10 milli volts per degree C, with 25 degrees C corresponding to 2.982 VDC. A reference circuit provides a zero reference voltage. It is adjusted to (2.982 volts - (25 degrees x 10 milli volts/degree) = 2.832 volts. To read the temperature of the LM335 directly in degrees C, connect the + lead from a high impedance DVM to the output pin and the end of the DVM to the 2.732 volt pin. The factor of 10 milli volts per degree C is equivalent to 10 milli volts per degree K, since a change of one degree C is equal to a change of one degree K. The difference in the two scales is only their offsets. The melting point of water ice is 0 degrees C and 273.15 degrees K. The boiling point of water is 100 degrees C and 373.15 degrees K.
The circuit consists of two parts: The LM335 and its adjustment. The output of the LM335 is 10 milli volts per degree C, with 25 degrees C corresponding to 2.982 VDC. A reference circuit provides a zero reference voltage. It is adjusted to (2.982 volts - (25 degrees x 10 milli volts/degree) = 2.832 volts. To read the temperature of the LM335 directly in degrees C, connect the + lead from a high impedance DVM to the output pin and the end of the DVM to the 2.732 volt pin. The factor of 10 milli volts per degree C is equivalent to 10 milli volts per degree K, since a change of one degree C is equal to a change of one degree K. The difference in the two scales is only their offsets. The melting point of water ice is 0 degrees C and 273.15 degrees K. The boiling point of water is 100 degrees C and 373.15 degrees K.
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