| 摘要 |
In a Wien-Robinson oscillator, a negative feedback path and a positive feedback path are arranged between the output of an operational amplifier and a reference ground potential. The negative feedback path contains two resistors which are connected in series and whose common circuit point is connected to the inverting input of the operational amplifier. The positive feedback path is formed from two RC elements which are connected in series and whose common circuit point is connected to the non-inverting input of the operational amplifier. If the aim is to keep the amplitude of the output voltage from the oscillator constant, additional measures are required, which increase the circuitry complexity. In order to stabilize the output voltage from the oscillator with little complexity, a third resistor is arranged between the output of the operational amplifier and that end of the positive feedback path which faces away from the reference ground potential. The common circuit point between the positive feedback path and the third resistor is connected via diodes which are connected in opposites senses, to a positive auxiliary voltage and to a negative auxiliary voltage. The magnitudes of the two auxiliary voltages are of the same magnitude, and the diodes are connected such that they limit the voltage at the common circuit point. Oscillators such as these are used, inter alia, for feeding inductive or capacitive movement sensors.
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