Electronic circuit basics

You need a continuous conductive path for electricity to flow in order to do something. The entire path that the electricity flows is the circuit.

Note: Never connect the terminals of a power source (such as a battery) directly together. That is called a short circuit and a dangerous amount of current will flow unless it is a weak voltage source. Always have a load that limits the current.

Incandescent light bulb circuit:

Light bulbs aren’t really ever used in basic electronics anymore, but they make a nice illustration circuit for beginners learning electronics.

• Light bulbs are rated for a voltage that can be applied to them. Simply apply that voltage and they will light up.
• Powering the light bulb can be done by using a battery or other power supply that is at the rated voltage of the light bulb or lower.
• Connections. There are light bulb and battery holders that easily allow conductive metal wires to make connections. You can also just touch the metal together to make an electrical connection for experimenting.
• Current: Once the circuit is closed (all needed connections are made), the voltage provided by the battery moves current through the whole circuit based on how much the light bulb limits the current based on the voltage. We imagine a fluid like force flowing from the positive side of the power source, through the wires, load, and back into the battery which keeps pumping the fluid through the circuit. We call that conventional current. After atoms and electrons were discovered, it was realized that electrons actually flow like a fluid from the negative side of the power supply to positive.

Related topics:

Other basic electronics topics that you should know before moving on to more advanced topics.

555 timer is an integrated circuit (IC). Being an IC, it has complex circuitry combined in a single package with external pins/terminals to connect to other circuitry. You can easily make all kinds of fun circuits with just a 555 timer and the components covered above, so I think it’s a good component to learn next.

Transistors will probably be the most challenging components to learn. Understanding them will help you understand all of electronics much better, and help you the most in being creative while designing your own circuits.

Other topics:

These pages are still being compiled.