transformers for electronics

2. • Transformers change electrical voltage.

3. Electricity is at high voltage levels for long
distance transport. That is why it is suspended
high above the ground.

4. High voltage electricity must be converted to
lower levels for safe use.

5. Power Transformers
Power line transformers changes power- plant
voltage to a lower level for consumer use.
On the pole On the ground

7. The Transformer changes voltage.
schematic symbol
123.9 VAC input 31.11 VAC output

8. How does it work?
No moving parts!

9. Magnetic Induction
is the Key.
One magnet can make
(induce) something else
to be a magnet.
The paperclip has
become a magnet.

10. Magnetic induction effect
Instead of a permanent magnet, the force
fields of an electromagnet are used.

11. Electrical Generation
One electromagnetic coil induces
electricity in another coil.

12. CONSTRUCTION
The input (primary) coil induces electrical
current flow in the secondary coil.
Notice the
two coils

13. Just three parts
Two coils of wire and an iron core.

14. Iron Core
The iron core focuses the magnetic
flux (field strength), making it stronger.

15. Types of Transformers
• Single tapped
• Center tapped
• Multi-tapped
• Step-up
• Step-down

16. Single tapped, Step-down
This is the most common type, used primarily
to lower line voltage.

17. Step-up
The output voltage is increased by making the
secondary (output) coil larger than the primary
(input) coil.

18. Center Tapped, Step-down
The secondary coil is tapped in the center,
dividing the output voltage by two.

19. Multi-Tapped transformers
several voltages can
be obtained from
one transformer.

20. Identify these types

21. Identify these types
center tapped, step down multi-tapped
step up single tapped, step down

22. Transformer Phase relationship
The secondary output
is 180 degrees out of
phase with the
primary (input).
The split secondary
outputs are 180
degrees out of phase
from each other.

23. • What is the power of the secondary?
• What is the voltage of the primary?
• What is the current of the primary?
• What is the power of the primary?

25. REVIEW
1. A center-tapped transformer has two, equal
voltage outputs.
2. Electricity from the generating plant must be
changed so it can be used at home, or on the job.
3. A transformer has only three main components,
the primary coil, secondary coil, and the core.
4. The primary coil is the input.
5. The secondary coil is the output.

26. Review Cont.
6. The working principle is electromagnetism.
7. The iron core conducts, and focuses the
magnetic flux so it is stronger.
8. The first, or primary coil, INDUCES electric
current in the second, or secondary coil.
9. Transformers can make electricity either higher
or lower voltage.
10. The magnets in a transformer are
electromagnets.