Inductor in DC and AC.

Phase angle of the alternating current in an Inductor,

The quality factor (Q)

Capacitor Discharge Process.

In a series RC circuit, a capacitor does not immediately discharge after being disconnected from a power source of direct current. The capacitor voltage Vc decreases from the initial voltage on the capacitor to 0 volts in some amount of time.

Capacitor and Direct Current.

Direct Current that varies over time, the current starts from a maximum value and decreases to 0 amperes, when there is no current flow. This happens in a very short period of time and is called “transient current”.

Series and Parallel Resistor Reduction.

Simplifing a series resistor circuit and / or parallel resistor circuit is simple, it is only necessary to make the necessary simplifications using formulas we already know

Benjamin Franklin’s Fluid Theory

Benjamin Franklin imagined the electricity as a invisible fluid.

Franklin assured that if any body had more fluid than usual, it could have a positive charge, but if it had less fluid than normal it had negative charge.

Current divider in parallel resistors The electric current passing through a circuit of two resistors in parallel is divided in two. Part of the current passes through the first resistor and the other part passes through the second one. The amount of current through a resistor depends on the value that the resistor has. In order to know what is the current passing […]

Voltage divider When two or more resistors are connected in series, the current that flows through them is the same. The equivalent resistor is obtained adding all the resistors values, and we can find the current using the Ohm’s Law: I = V / Rs, where Rs = R1 + R2 + R3 See the chart below where we find the original and the equivalent circuit. […]

The Superposition Theorem The Superposition theorem is used to find: The current values in a circuit with more than one voltage source. The voltage values at some point of a circuit that has more than one voltage source. The Superposition theorem states that the effect of two or more voltage sources in a resistor is equal to the sum of the individual […]

Millman’s Theorem The Millman’s equivalent circuit Many circuits have more than one voltage source, for example: Banks of batteries for emergency lighting, parallel power generators, etc.. Each of these sources of voltage has a different internal resistane. All these sources of voltage are connected to the same load. Look at the first picture (The original circuit diagram) The Millman’s Theorem shows us […]

Norton’s Theorem The Norton’s Theorem is similar to the Thevenin’s Theorem. It can be seen that, the equivalent circuit is: A Voltage source (Thevenin voltage: Vth) in series with a resistor (Thevenin resistance: RTH) Thevenin equivalent circuit This theorem says that the equivalent Norton circuit is a combination of a current source in parallel with a resistor. It is easy to find the Norton equivalent circuit when we […]

The Thevenin’s theorem The Thevenin’s theorem is used to convert a two terminal complex circuit, into a very simple circuit containing only one voltage source (Vth) in series with a single resistor (RTH). See pictures #1 and #5. Vth is called the Thevenin voltage Rth is called the Thevenin resistance and all together is called the Thevenin equivalent circuit The new circuit will […]

Ohm’s Law explanation Ohm’s Law can be easily understood if we analyze a circuit where there is a battery (12 volts source of voltage) in series with a 6 ohms resistor. You can establish a relation between the battery voltage, the resistor’s value and the electric current that passes through this resistor. This relation is: I = V/R and it […]