Primary Electrical Formula

The formula below shows the basic realtionship of the main factors in an electrical circuit. It is known as Ohm's Law. Ohm's Law in more exact definition deals with the relationship between voltage and current in an ideal conductor. This relationship states that: The potential difference (voltage) across an ideal conductor is proportional to the current through it.

I = E / R
Explanation of Terms

E - stands for voltage, the unit is the Volt.
I - stands for current, the unit is the Amp.
R - stands for resistance/impedance, the unit is the Ohm.

The formula below is derived (using variable substitution) from Ohm's basic formula using a new measurement that includes the value for power. You should see why the term volt-amp means watt.

P = I * E
Explanation of Newest Term

P - stands for power, the unit is the Watt.

Refer to these formulas and the diagram below when desiging your system to see how these equations come into play. In the diagram below, V is used for voltage instead of E.

Simple Circuit