1. Basic study of a switch Unit 3.Lesson 3

2. A switch Purpose A switch is a mechanical device used to connect and disconnect a circuit at will Parts seen from outside The casing or electrical box is a frame that holds and protects the device. It also provides insulation from electricity. The two poles, ends or contacts are metallic components that connects the switch with the electric circuit The toggle is an insulated lever button that allow to change the switch between on and off position

3. Switch view from outside Toggle Casing Poles, ends or contacts

4. How a switch works 1 On position A strip of metal (B) rests on the pole A of the switch. In the ON position, the other end of the strip contact with pole C, completing the circuit.

5. How a switch works 2 Off position When the toggle is moved to the OFF position, it pushes the metal strip away from pole C, breaking the circuit.

7. Switch exercises

8. Fill in the blanks exercise A ________ is a mechanical ________ used to _______ and __________ a _________ at will. The ________ or electrical box is a frame that _______ and _______ the device. It also provides _______ from electricity. The two _____, _______ or _______ are metallic components that connects the switch with the electric circuit The ________ is an insulated lever _______ that allow to _______ the switch between ___ and ___ position Toggle contacts device circuit casing holds off insulation connect poles protects ends change metallic disconnect button on switch

9. Switch parts exercise A___________ B___________ C___________