Electronics1

ELECTRICITY is... What??

A flow of ELECTRONS.

So, WHERE DO ELECTRONS COME FROM ?? and,
WHERE DO ELECTRONS GO??? AND WHAT DO THEY LOOK LIKE??

ANYWAY.. It works like this:
 
 Electrons come from SOURCES and go to LOADS.

Examples:

The 220 Volt AC power in a wall outlet SOURCE goes to a 100 Watt Light Bulb LOAD.
The 12 Volt DC power from a car battery SOURCE goes to a 20 watt Tail Light Bulb LOAD.
The 1.5 Volt DC power from the dry cell SOURCE in a flashlight goes to a 1/2 watt LED Flashlight Bulb LOAD.
The 3.7 Volt DC power from a Lithium Ion Battery SOURCE goes to a Digital Camera LOAD.

IMPORTANT ! !

LOADS must be matched to appropriate SOURCES or Bad Stuff Happens:

The LOAD doe not work properly, or at all. OR,
Ka-BOOM ! ! The LOAD is damaged or destroyed

CIRCUITS:

CIRCUITS connect SOURCES and LOADS together with CONDUCTORS. CONDUCTORS are usually wires, but may be any other conductive material such as a metal strap, the metal case of a flashlight, etc.

CIRCUITS can be simple, like a flashlight with one SOURCE connected in a circuit with one LOAD. Or, they can be very complex, like the wiring of Stage Lights, with many sources and many loads. Or they can be wicked complex, like a Pentium processor chip, with many millions of sources and loads.

We need to look at BASICS

Let's look at this example:

SOURCES of electricity: DRY CELL

A standard dry cell comprises a zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode.

WIRES - Conductivity

Wires are are usually made of Copper or Aluminum. Their Atoms are Conductive. The outer most shell for a given atom is called the valence shell. The conductivity of the atom depends on the number of electrons that are in the valence shell.

If the outer shell is FULL there are no Free Electrons. It is an INSULATOR
If the outer shell is not full there are Free Electrons. It is a CONDUCTOR

LIGHTS

Incandescent bulb - Hot wire glows - - LED (Light Emitting Diode) - Emits light from semiconductor surface

LED Long wire is +

ELECTRICAL CIRCUIT

SOURCE connected to LOAD

SWITCHES

Connect or DISconnect SOURCES from LOADS.

AlNahdaElectronics1

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