Low frequency Wien bridge sine wave oscillator(MC1456、μA741)

Published:2011/4/22 1:49:00 Author:Ecco | Keyword: Low frequency, Wien bridge, sine wave oscillator | From:SeekIC

Figure shows the low frequency Wien bridge sine wave oscillator circuit. The circuit uses the exponential characteristics of the diode to stabilize 0.001Hz sine wave generator amplitude, so as not to cause a larger time constant, because the diodes can quickly change their equivalent dynamic resistance. This stability is similar to the limiter. The 47kΩ resistor connecting to the diode in series is used to reduce the limiting effect of the diode, and can prevent the circuit distortion. In general Wien bridge oscillator, because of the limited input impedance of op amp, the R in the parallel RC can not be too high, so the oscillation frequency can not be too low. There are two op amps in the cirucit, RC is connected between the inverting input and output ens of op amp A1 and can increase the operational amplifier input impedance, so you can use a R with large resistance. The connection couldn't use FET input operational amplifier.



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