Basic Components

Electronics 2015

Batteries & Cells• Chemical devices that provide DC voltage

• A cell is an electrochemical device made of 2 electrodes of different materials and an electrolyte.

• A battery is 2 or more cells connected

Lamps• Commonly indicator lights

and illumination in cars,

planes, appliances,

flashlights

• Uses tungsten filament

wire to emit light when

heated by electric current

Indicator Lamp

Illumination Lamp

LED• Light-emitting diode

• Small, low powered and

reliable

• Polarity of leads need to be

determined before connected

Needs about 1.5 V and operates on 5-40 mA of current

Resistors• Most common and reliable components

• Major purpose is to control current and divide voltage

• Four categories:

1. Fixed

2. Variable

3. Adjustable

4. Tapped Resistors can vary from 1 Ω to over 100 M Ω

Resistor: Fixed• Power rating indicates the power a

resistor can dissipate without being

destroyed, this is determined by

physical size and material

• Squared off resistors are carbon-composition

• Rounded off resistors are metal-film resistors

• Rule of Thumb! Use a power rating

twice as great as the calculated value

Power Rating = Voltage2 ÷ Resistance

Resistor: Variable

• Potentiometer has 3 terminals, and rotation changes resistance between the middle and end terminals

• Rheostat has 2 terminals, adjusts current to a specified value

A potentiometer can become a rheostat by not using one of the end terminals

Potentiometer

Rheostat

Resistor: Adjustable• Similar to potentiometers and rheostats

• These are commonly used in high-power circuits (over 2 Watts)

• Only for infrequent resistance changes

Not adjustable when the circuit is in operation

30 Watt 10K Ω

Resistor: Tapped• Just like the adjustable resistors

• Commonly used in high-power circuits (over 2 Watts)

Not adjustable when the circuit is in operation

70 Watt 500 Ω

Resistor: Surface Mount

• Surface Mount Devices or chip components

• They do not have leads, soldered to traces on circuit board by their terminal pads

Power ratings don’t normally exceed ¼ Watt

Switches• All perform the same operation, to open and close a

circuit

• Can only exist in 2 states: Open or Closed

Push Button, Rocker, Slide and Magnetic

Switch: Momentary• Active if they are pressed or actuated

• Push buttons, joystick, keyboard

PBNO = Push Button Normally Open

PBNC = Push Button Normally Closed

Switch: Maintained• Stays on or off until it is switched

• Slide—Simple on/off selector switch

• Toggle—Long lever with rocking motion

• DIP—Not commonly used in modern

electronics (arcade games and video

cards)

Switch: Symbols• Poles—defines the #of circuits the switch can

control

• Throw—defines the #of positions the poles

can connect to

Capacitorhttps://youtu.be/ZYH9dGl4gUE

Bust A Cap!https://youtu.be/sW0a9d_vWoc

References

https://learn.sparkfun.com/tutorials/switch-basics?_ga=1.162470527.233046002.1431043005#switch-applications