Voltage Controlled Oscillator Using Op Amp

Single supply op amp voltage controlled oscillator square and triangular output signals.

Voltage controlled oscillator using op amp.

This circuit is a voltage controlled oscillator which is an oscillator whose frequency is determined by a control voltage. A 10 hz sawtooth oscillator provides the control voltage in this case. The working of this op amp relaxation oscillator can be explained as follows. The frequency of this waveform is varied by varying the magnitude of the input voltage.

Vco voltage controlled oscillator using opamps. After the water bucket is completely filled the entire mass on the bucket side will be more than the fixed mass m placed on the other end. By varying the input dc. This causes the frequency to rise slowly until it hits a maximum and then falls back to the starting frequency.

The first op amp works as an integrator. The oscillation frequency varies from few hertz to hundreds of ghz. The pulses can be used to advance digital counter or mechanical counter using a solenoid driver transistor circuit. It is an oscillator whose output frequency is directly related to the voltage at its input.

Once the tap is turned on the water flows into a water bucket thereby filling it slowly. A voltage controlled oscillator is an oscillator with an output signal whose output can be varied over a range which is controlled by the input dc voltage. A voltage controlled oscillator is an oscillator which produces oscillating signals waveforms with variable frequency. The first op amp is an integrator.

Lm339 is a quad comparator. Voltage controlled oscillator vco from the name itself it is clear that the output instantaneous frequency of the oscillator is controlled by the input voltage it is a kind of oscillator which can produce output signal frequency over a large range few hertz hundreds of giga hertz depending on the input dc voltage given to it. The other form of circuit for a voltage controlled oscillator is shown below which is implemented by using two operational amplifiers. It generates the square wave at the output whose frequency is determined by a control voltage.