| 摘要 |
PURPOSE:To make the output current constant independently of the phase of the output current by converting the output current into a voltage, rectifying the voltage, controlling the feedback resistor to the input side by a potential difference between a reference voltage and the rectified voltage based on the output current so as to adjust the amplification factor of the titled amplifier. CONSTITUTION:The output current i0 outputted from an output terminal 2 is converted into a voltage through a resistor R3 and smoothed by a capacitor 11 and made into a DC. The voltage is amplified by an operational amplifier 12. The output voltage of the operational amplifier 12 and the reference voltage adjusted/set in advance by a variable resistor 16 are given to an operational amplifier 13, where the difference between both voltages is amplified and the result is impressed to a light emitting diode 19. In this case, said potential difference being the output voltage of the operational amplifier 13 is increased corresponding to the increase in the output current i0. Then the input current to a photocoupler 18 is also increased and the resistance of a photoelectric transducer 20 is decreased accordingly. Thus, the resulting resistance of the feedback loop is decreased, the amplification factor of the amplifier is adjusted and the output current i0 being constant is obtained at the output terminal 2.
|
