| 摘要 |
<p>PROBLEM TO BE SOLVED: To make reducible a temperature drift by amplifying 2 output difference voltage of a magnetoelectric transducer driven by a heat-bonded constant current means, and controlling a mid-point voltage constantly. SOLUTION: The voltage of an output terminal of a Hall element 12 is divided, its voltage is applied to a non-inverting terminal of an amplifier 30, and a voltage of the other output terminal of the element 12 is applied to an inverting terminal of the amplifier 30 through a resistor 31. The difference voltage of the both is amplified by a differential amplifier 3, its gain is regulated by dividing an output of the amplifier 30 and negatively feeding back it. A temperature compensator 11 is heat coupled to the element 12 to increase or decrease a current value flowing from a positive power source to the element 12 according to rise or fall of the temperature of the sensor. The current from the element 12 is supplied to an output terminal of an amplifier 15, positive input voltage of the element 12 is applied to the inverting terminal through a resistor 16, the output voltage of the amplifier 15 is fed back through resistors 17=16, and the non-inverting terminal is grounded through a bias current compensating resistor 18. Thus, a mid-point voltage is controlled to the ground voltage.</p> |
