Op Amp Relaxation Oscillator

Today we are introduced to a new circuit device called oscillator. An oscillator is a circuit that produces an AC waveform as output when powered by a DC input. In order to make an oscillator, the Barkhausen criteria have to be met. The overall gain must be unity or greater. Therefore, loss has to be compensated for by an amplifying device. The overall phase shift has to be zero.

The Wien-bridge oscillator is a common type of oscillator. It is an operational amplifier circuit with resistors and capacitors in it. It it limited to operating in the frequency range of 1MHz or less.

Then we did a lab to build a operational amplifying. Here is a schematic of the circuit

Here is the setup of the circuit

Summary: Oscillators can be used to convert DC signals to AC signals. It can be achieved by using operational amplifiers. The charge and discharge of capacitors of the circuit generate the alternating circuit signal.