When you push the handle down, three things have to happen:
- Some sort of mechanism needs to hold the handle down to keep the toast inside the toaster for a period of time.
- Power needs to be applied to the nichrome wires.
- Some sort of timer needs to release the holder at the proper time so the toast pops up.
In this particular toaster, both the hold-down mechanism and the power switch are part of the handle:
Above you can see a plastic bar and a piece of metal attached to the handle. The plastic bar presses into a pair of contacts on the circuit board to apply power to the nichrome wires, and the piece of metal gets attracted to an electromagnet to hold the toast down. You can see both the contacts (copper strips on the right) and the electromagnet (green block on the left) below: