Science & Nature

When working with heavy-duty, high voltage electrical or electronic systems, the megger, more properly called a "megohmmeter," is used to test continuity and the insulation qualities of conductors...

Batteries come in many different types. The most popular one is that of a dry cell. Dry cells are found in various devices such as toys, cameras, radios, and desktop computers. A multimeter is a...

NAND gates are a common logic element used in many electronic circuits. The most common configuration is a two-input NAND gate, although configurations with more inputs are common. A NAND gate can...

Any electrical circuit generates heat. This heat is the result of current flowing through a resistance, and this phenomenon is found in toasters, light bulbs and high-voltage power...

In most of the world, household outlet voltage is 220 volts. In the United States and neighboring countries, however, household outlets run at 110 or 120 volts. This can pose a serious problem...

A volt is has been the common term of measurement of electric potential under the International System of Units for more than 100 years. Commonly used and commonly misunderstood, voltage is not a...

Diodes are made of a single crystal of a material, commonly silicon, divided into two portions. The first portion is n-type material, meaning that during manufacturing a small amount of a material...

When handled carelessly, high-voltage electricity can cause burns, internal injuries and electrocution death. When working on high-voltage electrical systems, it's important to remain aware of the...

Many high voltage outlets that are 220 to 240 volts typically have three openings. Two of them are live and ground respectively, and they are across from each other. They normally are slanted at...

A multimeter is a device used to make electrical measurements. One of the ways it can be used is to test an electrical outlet. You may test an outlet to see if electricity is actually going...

To check an electrical outlet, use either an outlet tester or a multimeter. An outlet tester is a small device used to test if a three-pronged outlet is working, and also if it is wired properly....

Faraday's Law describes the way in which moving a magnet through a coiled wire will induce voltage (a.k.a. electromotive force or "emf" for short). To calculate the voltage generated by a single...

Diodes are semiconductors that function as one-way valves. An ideal diode--called forward-biased--allows current to flow in one direction; a diode with current flow in the wrong direction is...

A square D transformer uses a squared loop or ring of magnetizable material as the medium through which electrical energy is transferred from one electrical circuit to another. The square D is...

Voltage (measured in volts) represents the difference of electric potentials that makes up the driving force of an electric current (measured in amperes, or amps). According to Joule's law, the...

Solar panels capture the heat of the sun and turn it into power. American homes commonly use solar power to heat water. Photovoltaic (PV) systems are used in many homes to heat water and provide...

As an induction motor, a torque motor converts electrical energy into mechanical energy--specifically, rotational force or "torque." Most induction motors need to rotate freely and continually...

Voltage (measured in volts) is the difference of electric potentials that is a driving force of the electric current, which is given in amperes. Joule's law defines electrical power as the product...

Just behind the protective layer of the lens, there is an infrared/ultraviolet light filter that blocks all incoming light that is not in the visible spectrum. This includes the IR-A, -B and -C...

Plasma balls are globes that light up with streamers of plasma from the center radiating out to the edge of the glass globe. They can be found at almost any novelty shop as well as several...

Diodes are semiconductor devices made from materials such as silicon. They allow current to flow in only one direction. Diodes can perform tasks such as emitting light, and can function as...

Fluorescent lights, unlike incandescent bulbs, need a regular supply of electrical current at a certain voltage in order to turn on. The way fluorescent lights create visible light is fairly...

The term "high voltage" usually refers to hundreds or thousands of volts, depending on the application. High-voltage power supply types can be internal in a piece of equipment or stand-alone for...

Digital multimeters are instruments commonly used to measure resistance, voltage and currents in electrical devices and circuits. They are preferred to analog ones because their digital display...

Digital multimeters are an essential tool when building and testing circuits. Their most common functions are measuring resistance, voltage, and current in electrical devices and circuits. Casual...

The average power transformer is essentially a circuit. The transformer translates high-voltage electricity into low-voltage alternating current electricity so that it can be safely used in homes...

Transformers are magnetic interfaces between circuits of different alternating voltage and current. The two circuits are connected by a magnetic core (a magnetizable block of matter) serving as...

Transformers change the current and voltage passing from one circuit to another. The transformer includes a magnetizable material, called a "core," that connects a primary circuit to a secondary...

Light-emitting diodes are commonly seen in our everyday lives. These small devices use less electricity than similarly sized incandescent lights. For that reason, LEDs are used for applications...

While certain varies of quartz can be very beautiful, the crystals in a "quartz watch" have nothing to do with aesthetics. Because of a physical phenomenon called the "piezoelectric effect," the...

Voltage meters measure the amount of potential electrical energy present in an energized circuit. One volt equals the potential to push one ampere of current through one ohm of resistance. Voltage...

Transformers are used to change the voltage of an alternating circuit. They do this by connecting two circuits at a magnetic core (a magnetizable block of matter). The ratio of windings the two...

Polarography is the study of electrode processes (or solutions) and is a subarea of voltammetry, a category of electro-analytical methods in analytic chemistry. Polarography involves electrolysis,...

A thermocouple is an electronic circuit that is used to measure temperature. A thermocouple uses two different metals to form a junction, which produces an electrical potential that can be...

An electromagnet is a current-induced magnet. The basic setup is an electrical current circulating around some magnetizable material, such as an iron rod. The current and number of times the...

Electrical diagrams range from the very simple to the very complicated, but they all are based on the same elementary principles. To learn how to read them, it is necessary to have a basic...

Transistors are made from semiconductors such as silicon or germanium. They are constructed with three or more terminals. They may be viewed as electronic valves because a small signal that is...

A diode is a semiconductor device that blocks current in one direction while allowing current flow in the other. A diode is symbolized by an arrow, to indicate the direction that the current flow...

Transistors are semiconductor devices with at least three terminals. A small current or voltage through one terminal is used to control the current flow through the others. They therefore may be...

Direct current (DC) is the flow of an electrical charge in one direction. Examples of this type of current include batteries and solar cells. Thomas Edison, who subsequently held many patents...

In building or understanding electrical circuits, it can be useful to calculate the voltage of a system from the wattage and current. Because watts are defined as volts times amps, as long as the...

Polynomials are equations of variables, consisting of two or more summed terms, each term consisting of a constant multiplier and one or more variables (raised to any power). Since polynomials...

Piezoelectricity is created when certain materials such as crystals are subjected to a mechanical force, thus causing them to generate a voltage. Piezoelectronics have important roles as...

A lemon battery requires an acidic fruit (lemon), a penny, a piece of zinc or a steel paper clip, two wires and a voltage meter. Two slits in the lemon hold the penny and and piece of zinc, each...

The potentiometer, often shortened to "pot" and originally referred to as a rheostat, is a device used to both measure electromotive force and control various electronic devices by adjusting the...

Transistors are semiconductor devices that have at least three terminals. A small current or voltage through the middle terminal is used to control the current flow through the others. They...

Diodes are semiconductor materials that behave like switches. They are open to electricity in one direction and short-circuited in the other, meaning that current is allowed to flow in only one...

Resistors are electrical components where the current (I) is proportional to the voltage (V). The constant of proportionality is R, the resistance. For linear resistors, V = IR, which is Ohm's...

Ammeters are electrical instruments that measure the current at a point in a circuit. They are usually inserted directly into the circuit line (series), but they can be parallel to the circuit,...

Diodes are semiconductor devices that allow current to flow in one direction only so that they function as valves. Common materials used in their construction include silicon, germanium and...