Day Twenty-One - No Lab, Day Twenty-Two - OP AMP relaxation oscillator

On day twenty one, we talked about how to analyse the circuit with AC signal using the old tricks we learnt in DC signal, all technique still apply to AC.

Hello guys, we talked about power today, WOOWWWOW.
Complex power sounds interesting, and the power factor is also interesting.
The power can be calculated by using the equations:

Also, today we talked about relaxation oscillator. Oscillator is a device which transform DC signal to AC signal. Without the existence of oscillator, AC signal will not exist.
A very simple design of oscillator is using op amp (comparator) and capacitor.
When the capacitor is charging toward the Vcc, the op amp switches, and output voltage saturates at
-Vcc. When the capacitor is charging toward the -Vcc, the op amp switches, and output voltage saturates at +Vcc, and this process will continue.

Pre-Lab:

We are planning to create a signal with the frequency 254 Hz; therefore we designed the belta value is 1/2, and we calculated the required resistor should approximately have 18k ohms.

EveryCircuit Model:

By implementing the circuit in everycircuit, we have successfully proven that the circuit will provide an oscillating signal.

Our measured value of frequency in our oscillator is 1/0.003740 = 267.3Hz.

Comparing to the theoretical and measured value, I think we have a good result with a small percentage error,  5.23%.

Summary:
One important point to note is that the average power absorbed by L and C are zero. Power in AC circuit involves both real and complex part, and the real part of the power has the actual meaning of power (Watt) while the complex power is just the "power" for the reactive elements.
Our lab, oscillator is a useful tool to create an AC signal, and the concept behind this device build up on our understanding from op amp and capacitor.