19 - Electric and Electronic Components

resistor

A device placed in a circuit to lower voltage and current flow.

liquid crystal display (LCD)

A device that has a fluid crystal material sandwiched between two sealed glass plates. This device can polarize light (make all the light waves vibrate in a single plane) to display numbers, letters, or other images.

fiber optics

A field of electronics in which light is used to carry data through small strands of plastic or glass fiber. Also, refers to cable that has light-carrying strands of plastic or glass.

relay

A magnetically operated switch that enables low current in one circuit to control (close or open) a greater current flow in a second circuit.

electronic component

A modern solid-state component that uses a semiconductor instead of moving parts while operating on one volt or less of electricity. Examples include diodes, transistors, sensors, and automotive computers.

photon

A particle of electromagnetic light energy.

photovoltaic cell

A photonic device that converts light directly into current. It consists of N-type and P-type semiconductor materials that can absorb light energy in the form of photons and an antireflective layer that helps it absorb more light energy, making it more efficient.

reverse bias voltage

A rating of the maximum voltage a diode can block without being damaged.

turns ratio

A ratio of the number of windings or wraps of wire in each transformer coil in a transformer.

diode

A semiconductor device that allows current flow in one direction, but resists it in the other.

transistor

A semiconductor device that can be used as a switch or an amplifier.

photoresistor

A semiconductor that acts as a resistor in the dark, but changes to a conductor when exposed to light.

N-type semiconductor

A semiconductor that is doped so that it has excess electrons.

P-type semiconductor

A semiconductor that is doped so that it has excess protons.

zener diode

A silicon diode that serves as a rectifier. It allows current to flow in one direction only until the applied voltage reaches a certain level, then the diode allows current to flow in the opposite direction.

semiconductor

A substance, such as silicone, that acts as a conductor or insulator, depending on its operating condition and application.

NPN transistor

A transistor that has two N-type semiconductors and one P-type semiconductor bonded together.

PNP transistor

A transistor that has two P-type semiconductors and one N-type semiconductor.

short circuit

An accidental grounding of an electrical circuit or electrical device, causing a tremendous amount of current through the circuit or device.

electric motor

An electric device that uses the principles of magnetism to produce powerful rotating action.

capacitor

An electrical component that absorbs voltage spikes by storing electrons, or electrical energy, thus protecting other vehicle electrical equipment.

coil

An electrical component that consists of insulated wire wound into tightly-spaced loops to create an electromagnetic field. Coils are usually wrapped around an iron core to strengthen the electromagnetic properties.

transformer

An electrical device that uses two sets of coils to transform voltage and current to higher or lower levels.

switch

An electrical device used to connect or disconnect the power supply in a circuit.

solenoid

An electrically operated magnetic device used to operate some unit. An iron core is placed inside a coil. When electricity is applied to the coil, the iron core enters itself in the coil and, as a result, it will exert some force on anything it is connected to.

bipolar junction transistor (BJT)

An electronic component that is made by joining three semiconductor materials. It can act as a switch for electronic signals or serve as a current amplifier.

phototransistor

An electronic device that conducts current through its emitter-collector junction when excited by light. When light is blocked, the emitter-collector junction changes to an insulator and blocks current.

wave

An increase or decrease (fluctuation) in voltage and current. The polarity of the voltage changes from positive to negative.

photonic device

Any device that can emit or detect light.

forward bias

Arrangement in which a diode acts as a conductor.

reverse bias

Arrangement in which a diode acts as an insulator.

brushes

Copper pieces that slide on the commutator to carry battery current to the spinning winding.

piezoelectric crystal

Crystalline ceramic material that produces a small output signal when exposed to physical strain or pressure.

fuse

Device that interrupts current if a circuit is overloaded or a short occurs.

circuit breaker

Device that interrupts current if a current is overloaded or a short occurs. Unlike a fuse, it can be reset.

impedance

Resistance to alternating current at a given frequency.

commutator

Segmented, sliding electrical connection between the armature windings and the brushes.

light-emitting diode (LED)

Special diode that lights when forward-biased. It, along with a photo diode, is used to produce an engine speed signal for the ignition system.

PN junction

The common edge of the P-type and N-type semiconductors.

armature

The core and shaft of an electric motor or alternator, consisting of electromagnets (known as field coils) and contacts (known as the commutator). As the armature rotates, the field coils change polarity to keep it rotating.

full-wave rectification

The process of converting alternating current to direct current allowing both halves of each AC wave through. Both halves flow in the same direction.

half-wave rectification

The process of converting alternating current to direct current allowing only half of each AC wave through. In this configuration, a single diode is used in series with an AC source.

rectification

The process of converting alternating current to direct current.

farad (F)

The size, or electrical storage ability, of a capacitor. A one-farad capacitor connected to a one-volt source stores 6.28 × 1018 electrons.