| 摘要 |
<p>PURPOSE:To accurately measure electric current, even when ambient temperature changes, by providing a temperature gradient setting section where the connection point of two resistors having the same resistance value but a different temperature coefficient is connected to an operational amplifier. CONSTITUTION:A temperature gradient setting section 4 comprises the first and second resistors 4a and 4b having an identical resistance value but a different temperature coefficient, and an operational amplifier 4c. The resistors 4a and 4b are connected in series between a power supply and the ground, and constitute a divided circuit for power supply voltage. In addition, a point P for the division, or the contact point of the resistors 4a and 4b is connected to one of the input terminals of the amplifier 4c. Also, the state of output voltage from a Hall element 20 in this constitution does not change, relative to the output voltage at normal temperature, even when ambient temperature rises or drops, thereby providing high measurement accuracy.</p> |
