25/01/23 16:15:35
@power-systems @physics @energy @study
Time: 50m
- I’ve a general understanding now of why we need to look at electricity.
- Think I need to try and get familiar with AC current and devices that it uses (induction motors).
- More generally, power in AC circuits.
- An AC emf is denoted by the fact that it’s not constant through time (unlike DC).
- It is oscillating between positive and negative peaks.
- We’ve seen before in (oscillators notes) that an oscillation or circular function is useful in describing something periodical. So can imagine the voltage function as drawing a circle.
- For a purely sinusoidal source the average power is .
- What if the source isn’t perfectly sinusoidal?
- Try and find the effective value of a periodic waveform. This is a constant value associated with the waveform.
- Like a DC filler for AC ?
- Similar to the average of a waveform.
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”The effective value of a sine wave produces the same I2*R heating effect in a load as we would expect to see if the same load was fed by a constant DC supply. “
- Not fully sure how this works out yet.
- Because the rms voltage becomes useful
- Rectifier: AC to DC.
- Inverter: DC to AC.
- Try and move on to understanding broad strokes of phasors. And then to the induction motor.
- Need to look at doing something practical.
Book: The Principles of Electronic and Electromechanic Power Conversion: A systems approach. https://www.electronics-tutorials.ws/accircuits/ac-waveform.html