Chapter 39-AC and DC devices

This chapter teaches about some of the practical devices that work on Alternating current (AC) and Direct Current (DC).

We show how an AC waveform looks, and circular motion equivalence to wave motion. An animation of a rotating turbine wheel in a hydraulic dam as the water falls, helps to understand how we get the AC upto our homes. Many more animations are presented to give a crystal clear grasp and confidence in the working principle of Generators, Motors, Transformers, as well as AC circuits like R, C, L, CR, LR and LCR circuits.

Following topics are covered:

1) Waveform for a current varying with time – what is it

2) A rotating pointer and AC Waveform

3) Fleming’s Left Hand Rule (for DC Motors) and Right hand Rule (for Generators)

• applied to a conductor LOOP

4) DC Motor

5) AC Generator

6) DC Dynamo : a DC Generator