how does trafo work?

How does a Transformer Work?
1. Electricity moving through the primary coil creates a magnetic
field.
2. This magnetic field induces (causes to happen) an electric
field and moves electrons in the secondary coil, thus producing
an electric current.


Primary coil Voltage = Secondary coil Voltage
# turns of wire in primary # turns of wire in secondary
Sample Problem 1:
Incoming (primary) voltage = 120 V
# turns of wire in primary = 75
# turns of wire in secondary = 150
Outgoing (secondary) voltage = ?
Sample Problem 1:
Incoming (primary) voltage = ? V
# turns of wire in primary = 9
# turns of wire in secondary = 30
Outgoing ( secondary) voltage = 400 V
Transformers that decrease the voltage are called step-down
transformers.
Transformers that increase the voltage are called step-up
transformers.