The Amateur Electrical Engineer

By Perry Henderson

Electricity serves as the basis for all modern development in the technological arena. The three primary fundamental aspects of electricity that the electrical professional or hobbyist must understand and have intimate knowledge of are: voltage, current, and resistance. One of the common metaphors that is constantly utilized in electrical power is to view electricity as something akin to water. If one keeps the imperfect but useful idea of electricity being similar in nature to water, it makes the understanding of circuits easier for the novice electronics or electrical practitioner.

Voltage which is measured in volts is the pressure that provides the push for electrons or electric current. Voltage in more scientific terms is the electrical potential difference. There is no current without voltage. Voltage moves current through the conductive material. A voltage source can be something such as a battery, which will provide voltage for the electrical circuit. Voltage can be seen as the pressure of water flowing through a pipe.

The close cousin of voltage is current. Current is simply the flow of electric charge in a conductor. The quantity of current is measured in amperes (A). Another way of looking at current is that it is the rate that charge passes a specified point in an electrical circuit. Charge is carried in conductive materials such as copper, gold, and silver. As in our previous example, the battery will push electrons through the conductive path and the flow of those electrons will be the current.

Finally, resistance is the quality of a material to slow the flow of electrons or electrical current. Current in physics and electrical engineering is measured in ohms (Ω). The amount of flowing current with a certain voltage is ultimately determined by the amount of resistance in the material. As we discussed in an earlier post, the relationship between these three quantities is described by the beautiful mathematical formula: Ohm’s Law. Ohm’s Law is simply V = IR. This law is the basic and primary law that all electronics enthusiasts should know and master. As a refresher: V is voltage, I is current, and R is resistance. The amateur electrical engineer who understands these basic principles can build almost anything they can imagine with electronics.

© Copyright 2025 Perry Henderson