| 摘要 |
PURPOSE:To make it possible to extract a signal faithful to the original waveform independently of temperature change, by connecting a temperature compensating element to the second input terminal of a voltage comparator even if the potential of the signal is changed by the temperature characteristic of the diode of a clamp circuit connected to the first input terminal of the voltage comparator. CONSTITUTION:The anode of diode 18 for temperature compensation is connected to power source terminal (c), and the cathode is connected to input terminal (e) of voltage comparator 16 and is grounded through resistance 20. The current from terminal (c) flows through diode 18 and resistance 20, and therefore, the potential of the cathode of diode 18, namely, terminal (e) of comparator 16 becomes lower than the voltage of the voltage source by forward voltage drop Vc of diode 18. In case of change of the ambient temperature, when forward voltage drop of diode 12 is changed by DELTAVd, the signal potential at terminal (d) is changed from waveform D by DELTAVd also. Then, the value of resistance 20 is so selected that forward voltage change of diode 18 may be equal to change of diode 12. |
