Various Types of Electronics Components

Voltage regulator

Description: Voltage regulators maintain voltage at a constant level even as the input voltage and the output load change. Voltage regulators typically have three pins: input, output, and ground.

Facts: The input voltage to a voltage regulator must remain high enough for the regulator to operate properly. If not enough voltage is available at the input pin, the regulator will not be able to sustain the required voltage. Voltage regulators often generate a great deal of heat and require heatsinks to operate at their full current capacity.

Photoresistor

Also known as: Photocell, electric eye

Description: A photoresistor is an electronic component that changes its resistance depending upon how much light it is exposed to at any given moment.

Uses: Photoresistors are used to sense when it is dark outside in order to turn on electric outdoor lighting. They can be used to detect the position of objects placed in front of them that are blocking a light source.

Facts: Photoresistors are commonly made out of cadmium sulfide (CdS). Cadmium sulfide is a semiconductor that more readily conducts electricity when light is present. The more light, the less the resistance. Photoresistors have a longer response time to changes in light levels than alternative light detectors such as phototransistors.

Potentiometer

Also known as: pot, rheostat

Description: A potentiometer is an adjustable resistor. Usually a screw or shaft can be turned in order to adjust the resistance of the potentiometer. A rheostat is a potentiometer used to control high power.

Facts: Many potentiometers have three terminals. The resistance between the two outside terminals is the same as the rating of the potentiometer. The terminal in the middle, called the wiper, is adjustable. The resistance between each end teminal and the wiper adds up to the rated resistance of the pot.

Bargraph LED

Description: A bargraph LED is a package containing multiple LEDs (light-emitting diodes) in a row.

Uses: Multiple LEDs can be lit, for example, to visually indicate a condition such as power level, temperature, or water level.

Red LED

Also known as: LED

Description: Light emitting diodes are diodes that are specially designed to emit light when current is applied in the forward direction.

Uses: LEDs are used in a wide variety of applications. They illuminate the numbers in digital clocks, serve as indicator lights on appliances, and provide light for some flashlights. Dozens, hundreds, or thousands of LEDs are combined to illuminate traffic lights, letter displays, and even some video displays.

• How Light Emitting Diodes Work

• What is a Light Emitting Diode?

Description: Triacs are solid-state on-off switches that are designed to control alternating current (AC).

Uses: Triacs are used in lamp dimmers and other applications where variable AC voltage is controlled by an electronic circuit.

Facts: Triacs are electronically equivalent to two silicon-controlled rectifiers (SCRs) connected in reverse-parallel.

Also known as: SCR

Description: Silicon-controlled rectifiers serve as solid state on-off switches. They consist of three terminals: the anode, cathode, and gate. A small current at the gate terminal switches on current between the cathode and anode. The SCR stays turned on until the current flowing through it drops below a certain level, known as the holding current.

Description: Transistors are used as amplifiers or switches, where a small current at one terminal is used to control a much larger current at another terminal.

Uses: Transistors are very commonly used in just about any electronics product or application.

Diode

Also known as: Rectifier

Description: Diodes conduct electricity in one direction only.

Uses: Diodes are very commonly used in just about any electronics product or application. They are used to protect against making connections with incorrect polarity and in voltage rectifiers that turn AC current into DC current.

Capacitors

Description: Capacitors store an electrical charge. Capacitance is measured in farads, or more commonly, microfarads.

Uses: Capacitors are very commonly used in just about any electronics product or application. They are commonly used for signal filtering, suppression of electrical noise, and in oscillators.

Resistor

Description: Resistors resist the flow of an electrical current. Resistance is measured in ohms. A potential difference of one volt will force a current of one ampere through a resistance of one ohm.

Uses: Resistors are very commonly used in just about any electronics product or application. Common resistors of the type pictured are typically rated to handle 1/8, 1/4, or 1/2 watt.