Analogue electronic components

Analogue electronic components

1. Resistors

   • Charateristics
     • Is a small cylindrical element
     • It used to limit the value of the current
     • And limit the voltage
     • The symbol is a rectangle
     • The colored rings painted indicate their value in coded form
     • The most common resistor is carbon film composed by the carbon helix and the ceramic cap
     • The resistor value is measured in ohms
   • When we use it?
     • To prevent LED from burning because resistors limit the voltage
     • To reduce the bulb luminosity the resistor reduces the electric current
   • Color code
     • Divided in four rings
       • The fist two indicate the initial figures
       • The third is a multypling factor
       • The last, the tolerance indicates the potential deviations in value
   • Potentiometer
     • Are variable and rotsry type resistors
     • May be adjusted between zero ohms and maximum value
     • the symbol is the same but it has an arrow in the middle
     • You can control the speed of an electric motor
       • We can see in the toy cars
     • Slide potentiometer
       • Control the volume of a speaker

2. Thermistor

   • Is a temperature sensor
   • The resistance change when the temperature changes
   • There are two types:
     • NTC for a negative temperature
     • PTC for a positive temperature
   • It used for the electronic termometres
     • To measure your corporal temperature

3. LDR

   • Is a light sensor
     • It has a very high electrical resistance when is in drakness
     • when is exposed in light the resistance drops
   • It works thanks to the semiconductors properties of a material called cadium sulfide
   • it used to create a photoresistance between to conductors
   • Is useful for example in the street lamps to turn on automatically

4. CAPACITOR

   • Suplies a small amount of electrical power to another component
   • The estructure is two metal plates separated by an insulation material
   • The most common capacitors are ceramic,electrolytic an polyester capacitors
   • If we connect the capacitor to a battery a meta plate will gain electrones and the other metal plate will lose electrons
   • But whe we disconnect, in both metal plates will be a flow o electrons so the capacitor is discharged
   • We can use it in a camera the battery charges the capacitor and the capacitor discharges doing the flash

5. DIODE

   • Is an electronic component that allows the electrical current to pass through it but only in one way
   • There are two types of semiconductors
     • N-TYPE
       • Antimony
       • Arsenic
       • Phosphorus
     • P-TYPE
       • Gallium
       • Indium
       • Borum
   • The most important Types of diodes
     • Photodiodes
     • Thermal diodes
     • Laser diodes
     • Light emmiting diodes

6. RELAY

   • Is an electromagnetic device
   • It works as a switch controlled by an electrical circuit
   • Parts
     • armature
     • Contact an electromagnet connections
     • electromagnet or coil
     • contacs
   • How it works
     • 5 An electrical current flow through the contacts and activates a device
     • 1 the relay at rest
     • 3 electromagnet generates a magnetic field
     • 4 The electromagnet attracts the armature
     • 2 electricity flows through the electromagnet

7. TRANSISTOR

   • Is a solid state electronic device that is used to control the flow of electricity
   • Usually consists of a small block of a semiconductor such as germanium with at least three electrodes
   • It has three terminals
   • We can use it as a amplifier
   • automatically opens and closes the circuit
   • Types
     • TO=92 CASE
     • TO=18 CASE
     • TO=220 CASE
     • TO=3 CASE