INS 11 - Powerplant and System Monitoring

Question 1

Whet are the three types of tachometer in use today?

Answer 1

• Mechanical,
• Electrical,
• Electronic

Question 2

How does the mechanical Tachometer work?

Answer 2

• A direct drive cable rotates with in a stationary sleeve
• The drive turns a magnet within an aluminium cup
• The rotating magnet sets up eddy currents in the cup which have their own magnetic field
• This produces a turning force of the magnetic field produce a turing force between the rotating magnet and aluminum cup
• The aluminium cup is opposed by a hair spring
• The aluminium cup rotates a pointer on the dial

Question 3

An tachogeneror can outut what three currents?

Answer 3

• DC Current
• Single Phase AC Current
• Triple Phase AC Current

Question 4

What are the two disidvantages in a DC Driven tachometer?

Answer 4

1. A Cimmutator and Carbon brushes to make contact that will lead to wear and tear, and sparking causing Communication interfererance
2. Line resistance causing voltage loss in transmission