How to Calculate Impedance

Impedance is one of the most difficult things the electronics technician student needs to calculate. To calculate impedance, you must know the value of all resistors and the impedance of all inductors and capacitors in the circuit. Then you can calculate impedance using a simple mathematical formula. More ...

EMI, RFI, EMC, EMS, What's the Difference?

EMI, RFI, EMC, and EMS all refer to different aspects of radio frequency interference which may cause elecronic devices to malfunction. Correcting these problems can be an art and a science. More ...

Bipolar Transistors

Transistors are semiconductor devices used to amplify or switch electronic signals. Transistors are one of the basic building blocks of modern electronics. There are basically two types of transistors, Bipolar Junction Transistors (BJT) and Field Effect Transistors (FET). More ...

Lead-Acid Battery Chemistry

As a lead-acid battery is repeatedly recharged, sulfation will build-up on the plates and the battery will begin to loose its capacity to restore to a full charge and eventually must be replaced. More ...

Junction Field Effect Transistor (JFET)

A Junction Field Effect Transistor (JFET) consists of a channel and a pn junction. The gate controls the conductance of the channel. A JFET is a voltage controlled device, therefore no current flows into the gate. More ...

Algebraic Order of Operations

In algebra if the same problem is done in a diferent order you will get a different solution. Order of operations is the rules that define conventions about which operations to perform first in order to evaluate a mathematical expression. More ...

Reduce, Add, Subtract, Multiply and Divide Signed Fractions

Algebra rules and examples about how to reduce, add, subtract, multiply and divide signed fractions. More ...

Direct Current

The nucleus of an atom is relatively heavy, so electricity primarily involves the flow of electrons. The nucleus of an atom generally doesn't move much. More ...

Silicon Controlled Rectifier (SCR)

A Silicon Controlled Rectifier (SCR) is a 4-layer diode that is controlled by a gate signal. It ca be turned on by a pulse on the gate. More ...

How to Add or Subtract Vectors

In mathematics and physics, the term vector refers to quantities that cannot be expressed by a single number. A vector has both magnitude and direction. A vector is represented by an arrow whose length is proportional to the quantity's magnitude, and whose direction is related to a property of the quantity. More ...

Inductor Mutual Inductance and Coefficient of Coupling

Mutual Inductance the property of a coil in which it opposes the change of current in another coil. The coefficient of coupling between two coils is the fraction of magnetic flux produced by the current in one coil that links with the other coil. More ...

Introduction to Angles: Acute, Obtuse, Straight, and Right

An angle is the amount of turn between two lines around thethe vertex. The name of an angle uses an angle symbol followed by three letters. The letter from one side, the letter from the other side, and the letter of the vertex. The letter of the vertex must go in the middle. More ...

What Is an Electronic Circuit?

Circuits provide a path for current to flow. To be a circuit, this path must start and end at the same point. In other words, a circuit must form a loop. More ...

RMS Used in AC Circuit Analysis

Because the value of an AC signal is continuously varying, it would be difficult to use formulas such as ohms law. In the specific case of a sine wave, the Root Mean Square (RMS) of the wave is used instead. More ...