Alternators, Dynamos & Oscilloscopes

• dynamos produce direct current. alternators produce alternating current.
• Differece

  A) Dynamo

  B) Alternator

  
• How alternators work:

  1. The coil of wire rotates relative to the magnets, this induces a magnetic field in the coil, which then induces a voltage and current in the coil.
  2. The slip rings and brushes mean that the contacts don't swap every half turn (like they do in a motor or dynamo).
  3. This means that they produce an alternating potential difference and an alternating current (a.c.).
  4. As the coil rotates faster, the peaks of the oscillations get larger, and more frequent.

  
• oscilloscope - the device for viewing changes up and down
• How dynamos work:

  1. As the coil of wire spins relative to the magnet, a magnetic field, and hence a voltage and current, is induced in the coil.
  2. The split ring commutator means that the contacts swap every half turn.
  3. This means that they produce a direct potential difference and hence a direct current (d.c.).
  4. As the coil rotates faster, the peaks of the oscillations get larger and more frequent.

  
• Induction - generating current in a conductor by placing it in a changing magnetic field