Science & Nature

Invented by electrical engineers in the late 1800s, circuit breakers automatically disconnect circuits when they're overloaded. Inexpensive, reliable and reusable, they are available in standard...

Electrical switches are used to control the flow of electrical current in an electrical circuit. A "closed" switch enables electrical current to flow through the electrical circuit; "opening" a...

Circuit breakers and fuses perform the same basic function, to automatically relieve an overloaded circuit. Circuit breakers do more and cost more. Fuses are simple and inexpensive. They each have...

A circuit breaker is a protective electrical device that opens a circuit when overloaded. Circuit breakers have replaced fuses in most home, commercial, and industrial electrical applications....

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...

A transistor is a semiconductor device that is used in many electronic applications. Transistors are primarily used in two ways: as a switch or as an amplifier. A particular type of transistor,...

When your running lights go out and you're trying to find the cause, remember that all troubleshooting follows the same steps: Verify that there is a real problem; find out what's happening and...

A very simple doorbell can be constructed by creating a circuit that is completed or broken by the press of a button. This is basically how all doorbells work. The oscillation of the circuit's...

From a child connecting a battery, switch and light in a simple circuit to an adult building robots, the field of electronics provides an entertaining, hands on hobby, accessible to all ages. This...

A transformer is used to change the voltage and current from an energy-supplying circuit to a receiving circuit. A magnetizable piece in between called a "core" is used to transmit the energy...

A fuse is an electrical component used in an electrical circuit for safety reasons. A fuse opens the circuit, or prevents the flow of electrical current, when conditions exist that will cause the...

Transformers change the current and voltage passing from one circuit to another. The primary circuit is driven by an electromotive force, which is then transferred through a magnetizable...

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...

Lemon-powered clocks work by using the process of electrolysis. The lemon juice is an acidic electrolyte, which is then connected in a circuit through a metal electrode. There must be two...

A parallel circuit has more than one path for current to flow through. To calculate the ohms (or resistance) in a circuit, a simple formula is used. Each path can have a different resistance, and...

Invented in the 1930s, the printed circuit board continues to improve and evolve. Most soldering is now completely automated, speeding assembly and reducing costs. Lead and other hazardous...

Electrical relays are useful to us in many ways. These electrically actuated devices are used in automobiles and industrial applications to control whether a high-power device is switched on or...

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...

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...

A current transformer is used to measure the current of a circuit into which an ammeter cannot be directly inserted. Transformers consist of two circuits linked with magnetizable material called...

Thermocouples are temperature sensors that are made from two different metals. A voltage is generated when the metals are brought together to form a junction and there are temperature differences...

A potentiometer is an adjustable electro-mechanical transducer. The user can adjust a potentiometer freely; the adjustments made change the resistance over a circuit. As part of a circuit the...

We use stereos, telephones and MP3 players on a daily basis. However, none of those would be useful to us if we couldn't hear the output of those devices. Audio amplification technology gives us...

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...

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...

An electrical transformer changes the current and voltage levels in an alternating circuit using magnetic induction. You can make a homemade transformer with simple tools. No need to have the...

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...

An electrical transformer is used to increase or decrease the voltage of an alternating current. A transformer requires an alternating current (AC) to work, such a wall socket. The structure of a...

Resistors are electrical components designed to limit the amount of current flow in circuits. The values of their resistance may be either fixed or variable. Fixed resistors share common elements...

Ammeters and voltmeters are based on the galvanometer, a device that is used to detect small currents. Galvanometers that are calibrated to measure currents of different amounts are called...

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,...

You can easily identify a direct current (abbreviated "DC") circuit when you know what to look for. It is the basic building block of modern electronic gadgets. Let's briefly explore the history...

A phase vector, or phasor, is a representation of a sine wave whose amplitude, phase and frequency are time invariant. The projection of phasors onto the vertical axis gives their instantaneous...

A transformer changes voltage in an alternating circuit. Because power loss equals current-squared times resistance, this allows transmission of large amounts of electricity with high voltage to...

Resistors are electrical components, usually conductors, that help control current flow in a circuit. A high resistance means that there is less current available for a given voltage. Resistors...

The decision whether to use AC or DC coupling comes up often in circuit design. Fortunately, it is simple to sort out. You' will need to look at the kinds of signals you are dealing with. If you...

Different materials conduct electrical current with differing facility. For example, increasing the mix of carbon in a ceramic resistor reduces its resistance. Because of the wide range of...

Circuit breakers are devices used to allow current to move along a circuit or, in the event of a surge or short circuit, to stop the current flow. Circuit breakers are standard in most modern...

Electric circuits are made with the use of electronic components connected to each other by conductors such as wires or solder. The purpose of the components is to manipulate and control current...

A current transformer (CT) is a transformer which measures the current of another circuit. It is coupled to an ammeter (A in the diagram) in its own circuit to perform this measurement. ...

Selling gold items can help a person get through difficult financial times. Gold buyers use several types of scrap gold for recycling purposes. Jewelry, coins, electronics and metal alloys are the...

Electric circuits are made using electronic components that are connected to each other by conductors. These components manipulate and control current in various ways by performing duties such as...

Electrical components or devices are parallel to each other when they are connected to the same two points. For resistive devices that obey Ohm's Law, the current is divided among them, but they...

All electrical devices use voltage and current for the operation of that device. The product of these two distinctly different electrical characteristics is watts. The mathematical formula for...

Have that brilliant circuit in mind? You know, the one that will regulate your amp's bass while making your toast at the same time? Chances are they don't sell that one pre-made. Knowing how to...

Resistance is part of Ohm's Law, the basic law of electronics: Voltage equals Resistance times Current, V=RI Unlike voltage (whether supplied by battery or power supply) and current, a resistor...

Simple circuits are constructed with a few basic circuit components. They include a power source such as a battery, wires or clips to connect the circuit elements and a component load. They can be...

The first transistor was invented in 1947 by John Bardeen and Walter Brattain, who were employees of Bell Telephone Laboratories. In an experiment intended to gain an understanding of how...

A parallel circuit has one function: to keep the electricity flowing when one pathway is interrupted. A prime example is light fixtures that use multiple light bulbs. When a single bulb in the...

An oscilloscope is a device which graphically displays a repeated waveform in a circuit, such as the signal for a sound. Oscilloscopes display the voltage or amperage of a circuit as a line on a...