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
<<NOT gate<< | <<AND gate<< | <<OR gate<< |
---|---|---|
If the input is one state, the output will be the other state. | If both of the inputs are high, the output will be high; otherwise the output will be low. | If either of the inputs is high, the output will be high; otherwise the output will be low. |
NAND and NOR gates
<<NAND gate<< | <<NOR gate<< |
---|---|
If both of the outputs are high, the output will be low; otherwise the output will be high. | If either of the inputs is high, the output will be low; otherwise the output will be high. |