Chapter 10: Electrons and Electronic 

Electronic Components

• Resistor keep currents and voltages at levels needed for other components to work properly.
• Capacitor store small amounts of electric charge.
• Diodes let current flow in one direction only.
  • Can be used to change AC circuit to DC circuit. This process is called ==rectification==.
  • such diodes are known as ==rectifiers.==
• Light Emitting Diodes (LEDs) glow when a small current passes through them.
• Transistors are used for amplifying signals for switching.
• Integrated Circuits many complete circuits, with ==resistors==, ==transistors==, other components, and connections all formed on a tiny chip of silicon only a few millimeters square.
• Relays are ==electromagnetic switches==.
• Reed Switch is operated by a ==magnetic field.==
  • It is operated by a magnetic field.
  • When a coil round it, a reed switch becomes reed relay.

Electronic Switching

A light sensitive switch

• It is a special kind of ==resistance== falls when light shines on it.

• When the LDR is put in dark the lamp lights up.

  

A temperature sensitive switch

• It is a special kind of resistor whose resistance falls considerably when temperature rises.

• In the below circuit when temperature increases and thermistor heats up; the bell rings.

  

Logic gates

AND, NOT and OR gates

NAND and NOR gates