| 摘要 |
PURPOSE:To facilitate the adjustment for an output voltage, by an operational amplifier and a bridge circuit including three variable resistors. CONSTITUTION:A reference voltage generating device consists of an operational amplifier 8 and a bridge circuit consisting of a resistance R1 and variale resistors VR1-VR3. When resistances 6, 7, 11 and 12 are set to set the gain of the operational amplifier 8 to 1, an output voltage V3 is equal to V2-V1. For the adjustment of the output voltage, the value of the variable resistor VR1 is set to zero, and the value of the variable resistor VR2 is so adjusted that the output voltage V3 becomes a maximum value in a required voltage range. Next, the value of the resistor VR1 is set to a maximum, and the value of the variable resistor VR2 is so adjusted that the output voltage V3 becomes a minimum value in the required voltage range. Thus, the output voltage is varied stably between the minimum value and the maximum value only by adjusting the value of the variable resistor VR1. |
