Basic Electronics

Ohm’s Law

a reminder that basic electronic circuits follow Ohm’s Law to some extent.

              Ohm’s Law       V=I/R    

Ohm’s Law fails when significant temperature changes occur or when certain “non-ohmic” materials are used

POWER
Power is simply the energy required to do something. If you are moving a large number of electrons and moving them through something that is resistant to that movement, power is used. Power is voltage times current. Power is also voltage squared divided by resistance. In electronics, we use the flow of electrons to drive a variety of processes.

P = I x V

Power = Watts/time

P = V²/R

Resistors
A resistor is a component that resists the flow of current. It's one of the most basic components used in electronic circuits. If you put resistors next to a penny, you get an idea of how small they are.

Capacitors
Next to resistors, capacitors are probably the second most commonly used component in electronic circuits. A capacitor is a device that can temporarily store an electric charge. 

Diodes
A diode is a device that lets current flow in only one direction. A diode has two terminals, called the anode and the cathode. Current will flow through the diode only when a positive voltage is applied to the anode and negative voltage to the cathode. If these voltages are reversed, the current will not flow.

Light-Emitting Diodes
A light-emitting diode (or LED) is a special type of diode that emits light when the current passes through it.

Transistors
A transistor is a three-terminal device in which a voltage applied to one of the terminals (called the base) can control the current that flows across the other two terminals (called the collector and the emitter). The transistor is one of the most important devices in electronics.

Integrated Circuits
An integrated circuit is a special component that contains an entire electronic circuit, complete with transistors, diodes, and other elements, all photographically etched onto a tiny piece of silicon. Integrated circuits are the building blocks of modern electronic devices such as computers and cellphones.