I want to ask how dc motor and ac generator work and how they are used.
dc motor is a device that converts electrical energy into mechanical energy. dc motor consists of magnet, coil, split ring commutator, brush and dc supply. dc supply will give direct current to the coil and magnetic force will act on the coil, make it rotates, let say clockwise. The split ring commutator will reverse the direction of the current round the coil every half-turn so that the coil will keep rotating clockwise.
1. We call it dc motor because the supply used is dc? If the supply is AC then it is AC motor?
2. What is the application of dc motor? If the function is to convert electrical energy to mechanical energy, it means that we use the mechanical energy for something, what is it?
Now about ac generator. ac generator converts mechanical energy into electrical energy. ac generator consists of magnet, coil, brush, and slip rings. The coil will rotate and produce electricity.
1. I don't understand why the coil can rotate. I suppose the concept is the same as dc motor, using magnetic field and current to produce force and then produce turning effect. But if it is true, then the coil must be connected to power supply to get current so we basically change electrical energy to mechanical energy then to electrical energy. I am sure my concept is wrong but I don't know what the mistake is.
2. ac generator used concept of electromagnetic induction to produce electricity. How does it apply the concept? My opinion is because the coil rotates, it will cut the magnetic field so emf will be induced in the coil. Slip rings will transfer the emf produced by the coil to external circuit. And because the emf induced is alternating, the current produces also alternating. Am I correct?
3. If my opinion above is correct, then the coil in dc motor will also cut the magnetic field and emf will be induced on it. So dc motor also can produce electricity?
Ahhh, I'm so confused :grumpy: