NAND gate – Truth table.

NAND gate, also called universal gate, is a gate that produces a logic “0” output only when all logic inputs are “1”. Truth table.

Mesh Current Method in a Resistor Network

The Mesh current method is very useful to know all the current  in a network of only resistors. This method, a little more extended, is also applied to circuits where there are resistances and reactance.

What is a Millman’s Theorem?

Millman’s theorem is used to directly obtain the voltage between the ends of a parallel branch circuit. Equivalent Millman circuit Formulas, example.

Window comparator using op amps

A window comparator using operational amplifiers lets you know if a signal (voltage level) is within or outside a previously defined acceptable voltage limit. Using a comparator or operational amplifier that controls the upper voltage level and another comparator that controls the lower voltage level, a window comparator can be implemented.

Push – Pull Amplifier

A Push – Pull amplifier is called that way, because it uses 2 groups of transistors and only one works at a time. One group pushes in one direction while the other pulls in another direction. Each group is responsible for amplifying a single phase of the input wave.

Why is the transformer core made of metal sheets?

Explanation of why the electric transformer has a core made of iron sheets. Eddy or Foucault’s currents

Capacitor charging process

Capacitor charging process shows the variation of voltage and current in the capacitor over time, when it is connected to a DC voltage source

Parallel RC circuit

Voltage, Currents, Phasor diagram & Impedance. Voltage is the same on the capacitor and resistor. Current is ahead of the voltage in the capacitor

What is a Truth Table?

The Truth Table is used to simplify boolean equations obtained from digital circuits. The truth tables can have many columns, but all tables operate in the same way.

Basic structure of the sinusoidal oscillator

The sinusoidal oscillator basic structure consists of an amplifier (A) and a selective frequency network (ß) connected in a positive feedback loop

Amplifiers and Amplification

Amplifiers are circuits that are used to increase an input signal, thus you can obtain an output signal with much greater amplitude than the original one. Amplification is the process to increase the magnitude of a signal, generally using an amplifier.

The series RC circuit.

In a series RC circuit, the current through the resistor and the capacitor is the same. The voltage VS is equal to the phasor addition of the voltage drop across the resistor (Vr) and the voltage drop across the capacitor (Vc).