| 摘要 |
PURPOSE:To accurately set a gain by providing an N-P-N transistor connected at the emitter through two series resistors connected with -input of an error amplifier through a feedback resistor at the connecting point with a ground. CONSTITUTION:An AC frequency which is proportional to the rotating speed of a motor 1 output from a frequency generator 2 is converted by a F/V converter 3 to a DC voltage. An error amplifier 4 voltage/current-converts the difference between the output of the converter 3 and a reference voltage Vref through an N-P-N transistor 5 and resistors R0, Re, and supplied to the motor 1. The connecting point of the resistors R0, Re is connected through a feedback resistor Rf with the negative input of the amplifier 4. Thus, the gain of a voltage/current converter can be accurately set. |
