| 摘要 |
PURPOSE:To achieve an accurate temperature compensation regardless whether the temperature coefficient of a signal to be detected is either positive or negative by enabling connection to the second temperature compensation circuit switched from the first temperature compensation circuit with the point of inflexion of the signal to be detected as boundary. CONSTITUTION:A comparator A4 produces a positive output when the temperature to be detected with a thermistor Th is lower than the temperature at the poit inflexion of a signal Si to be detected and an output '0' when it is higher than that. When the positive output is produced, transistors Tr1 and Tr3 conducts to be driven allowing a thermosensitive element RT to be connected to a feedback circuit of an arithmetic amplifier A2. This forms a first compensation circuit to effect a temperature compensation for a signal Si to be detected having a positive temperature coefficient. On the other hand, when the comparator A4 produces an output '0', an inversion takes place with an inverter IN and transistors Tr2 and Tr4 conducts to be driven allowing a thermosensitive element RT' to be connected to a feedback circuit of the arithmetic amplifier A2. This forms a second temperature compensation circuit to effect a temperature compensation for the signal to be detected having a negative temperature coefficient. |
