The document summarizes the history and components of a basic electric toaster. It then describes the step-by-step process of how a toaster works: (1) the user plugs in the toaster and turns the switch, (2) slices of bread are inserted into the slots, (3) pressing the handle closes the contacts and starts heating the nichrome wires, (4) springs and an electromagnet hold the bread in place as it toasts, and (5) after the set time the electromagnet cuts off power, allowing the springs to eject the toasted bread.

1. Techno-
logy of a
Toaster
(for dummies)
Judith Lievens

2. Content
HISTORY
PARTS
SO WHAT HAPPENS WHEN I TOAST MY
SLICE OF BREAD?

3. HISTORY

4. History
• Why ?
• Electricity in America
• 1900 Embedded heating
• 1905 Nichrome (Albert Marsh)
• 1909 First electric toaster (Frank Shailor for
General Electrics)
• 1913 Toaster with automatic turner (Lloyd
Copeman)
• 1919 Automatic pop-up (Charles Strite)
•1928 Pre sliced bread
• 1933 Spring loaded automatic toaster in
households
• 1960’s Common and cheap

5. History

6. PARTS

7. Parts Shell

8. Parts Shell - Handle

9. Parts Shell – Switch&Options

10. Parts Shell - Slots

11. Parts Bottom

12. Parts Crumb Tray

13. Parts Inside
Handle connection
Plastic tab
Contacts
Metal tab
Electromagnet
Springs
Selfpositioning slot
PCB

14. SO WHAT HAPPENS
WHEN I TOAST MY SLICE
OF BREAD?

15. So what happens…
With a HEMA toaster

16. So what happens…
1. Plug in the toaster
2. Turn the switch
3. Optionally pick ‘bagel’, ‘defrost’ or ‘reheat’
4. Place your slices of bread
5. Push the tray down with the handle
6. Wait or push ‘stop’
7. Take out your bread
8. Empty crumb tray
9. Pull out the plug
10. Eat it!

17. So what happens…When you turn the
switch?
Variable resistor

18. So what happens…Pick an extra option?
Extra resistors
LED

19. So what happens…When I push down the
handle?

20. So what happens…
Plastic component ↓
Lubicant axes
When I push down the
handle?

21. So what happens…
Contacts close – lubicant – electrical circuit
When I push down the
handle?

22. So what happens…
Nichrome wires start toasting
When I push down the
handle?

23. So what happens…
Electromagnet – metal tab
When I push down the
handle?

24. So what happens…
Selfpositioning slot
When I push down the
handle?

25. So what happens…
Selfpositioning slot
When I push down the
handle?

26. So what happens…
Spring 1: stretches Spring 2: moves
down
When I push down the
handle?

27. So what happens…
Capacitor charges
through resistor
= timer
When I wait?

28. So what happens…
Electromagnet is cut off and lets go
When I wait?

29. So what happens…
Spring 1: relaxes Spring 2: stops
components
When I wait?

30. So what happens…
Plastic tab – pulled upwards – contacts broken
When I wait?

31. So what happens…
Power to
nichrome wires
cut off
When I wait?

32. So what happens…
Selfpositioning slot
When I wait?

33. So what happens…
Selfpositioning slot
When I wait?

34. So what happens…
Normal Closed
↓
Power is cut off
Electromagnet releases tray
Springs relaxes and pulls up
the tray with toast
Contact for nichrome wires
is broken
…
When I push ‘stop’?

35. So what happens…When I eat my toast?