BT- ELECTRICAL (Light and Fire Control)

Compre reviewer

Light

The form of electromagnetic radiation that allows the eye to see.

Illuminance

the amount of light striking a surface

Luminance

the amount of light leaving an object; it is how bright an object appears.

Reflectance

is the ratio of reflected light versus the light striking the surface.

Specular

occurs when light is reflected off a polished or mirror-like surface wherein the reflected image is maintained.

Diffuse

results when reflected light is scattered after striking the surface.

Transmittance

– is the ratio of light transmitted through the body versus the light

illuminating the surface.

Transparent body

transmit light through it without distorting the image

(e.g. clear glass)

Translucent body

– transmit light but obscures the image because light is

scattered (e.g. obscured glass)

Absorptance

– is the ratio of the light absorbed versus the light striking the

surface.

Opaque body

– illuminance will be reflected and absorbed but will not be

transmitted.

Color Perception

ability to distinguish and interpret different wavelengths of

visible light.

dominant wavelength

The perceived color of an object depends on the _____________that luminate from it.

bright, black.

In natural light, a surface that reflects all wavelengths appears _____ while a surface that absorbs all wavelength appears _______

Visual Acuity

– ability to distinguish fine details; it is the keenness of vision

necessary to perform tasks like reading, writing, drafting or surgery.

Luminous Flux

measure of perceived power of light expressed in lumens

Luminous Intensity

the power emitted by a light source in a particular

direction expressed in candela

Luminous Intensity

improperly called as candlepower.

Luminous Efficacy

– ration of light output of a lamp into the electrical

energy consumed;

Luminous

use to determine efficiency of a bare lamp.

Color Rendering Index

– is a method of numerically comparing the color

distribution of a light source to a reference lamp.

Correlated Color Temperature

is the temperature of a lamp in kelvin (k)

Warm lighting

– less than about emitting mostly red and yellow

wavelengths.

Cool lighting

greater than about emitting mostly blue and white

wavelengths.

Daylighting

temperature is between with the lower side warmer

and the upper side cooler; noon sunlight; candle frame.

Daylight

Used where color matching is

important; equivalent to a

north sky; not in general use

because of high proportion of

blue

Cool White

Combines high efficacy with

good color rendering; used in

factories, offices, schools;

rather cold in appearance

Deluxe cool white

Less efficient than daylight by

20%; has better color

rendering properties in the

long wavelengths; used in

stored and some factories

where color is important

White

Highest efficiency lamp; often

used in factories and offices

Warm white

High efficiency lamp; only

moderate color rendering;

poor with reds – emphasis is

yellow and yellow greens;

used in offices

Deluxe warm white

Most efficient lamp; closest

approximation to tungsten

filament color rendering;

suitable for homes,

restaurants, hotels.

Lamp

device that generates light

Bulb

glass portion of the lamp

Luminaire

complete lighting unit

Fixture

luminaire without the light

Filament Lamps

Produces light by passing electrical current a filament

INCANDESCENT LAMPS

Composed basically of a sealed glass containing a filament connected at its ends to the contact area in the base thereby completing an electric circuit.

INCANDESCENT LAMPS

Emit visible light as a result of heating.

A

Standard (INCANDESCENT LAMPS)

ER

Ellipsoidal reflector (INCANDESCENT LAMPS)

R

Reflector (INCANDESCENT LAMPS)

G

Globular

S

Straight

T

Tubular

PS

Pear-shape

F

Flame

PS 30 Lamp

is a pear-shaped bulb 30/8 or 3-3/4” in diameter.

TUNGSTEN-HALOGEN LAMPS

Lamps are hotter-burning incandescent lamps.

TUNGSTEN-HALOGEN LAMPS

These lamps use a halogen gas cycle to prevent

rapid depreciation of the lamp filament and

darkening of the transparent envelop.

TUNGSTEN-HALOGEN LAMPS

Are similar, brighter, and more expensive version

of the incandescent; contains high-pressure

halogen gases such as iodine or bromine.

Gaseous Discharge Lamps

Produces continuous light by passing electricity through a gas contained within the

lamp; the electric discharge produces ultraviolet radiation that causes a phosphor

coating on the inside of the lamp to glow.

FLUORESCENT LAMPS

Composed of tubular glass bulb that is covered with thin phosphor coating

on its inside surface.

FLUORESCENT LAMPS

The glass bulb is filled low-pressure mercury vapor; are equipped with

filament-like coils at the ends (Cathodes).

ballast

All fluorescent light sources require a control device or an auxiliary, called

ballast

located in the metal base; it consumes about 20% energy.

ballast

-Supplying the high voltage necessary to start the arc;

-Limiting the current in the arc after it is formed.

starter

For the operation of fluorescent lamps, an automatic switch known as a

_________ is required, in addition to the normal wall switch.

starter

self-

contained in a small tubular jacket which is inserted in the fixture body and

is a replaceable part.

Linear Fluorescent Lamps (LFL)

available in straight, U-shaped and

circular

T12, T10, T8, T6, T5, T4, T2

are commonly used straight tubes (LFL)

T9

are used for circular lamps. (LFL)

20%

lamps deliver almost the same amount of lumen output for about ____ fewer watts than T12, and have

higher lumen maintenance.

Pre-heat

Requires a starter which preheats the cathodes so that less voltage is required to strike an arc.

2-5 seconds

There is a ___________ delay in the start of lamp after switch is on. (Pre-heat)

Pre-heat

also called a “switch-start” or “starter-start” lamp.

“trigger-start ballast”

In certain cases, the started can be eliminated by using a device called a_______________

Instant Start

When the lamp is first switched on, a sufficient voltage is

applied between the electrodes to strike the arc without

preheating them.

Instant Start

starts as soon as current is turned on and

eliminates the need for external starters.

Instant Start

They have single-pin bases which are called “slim-line”

lamps.

Rapid Start

use low-resistance electrodes which can

be heated continuously with low current loses.

Rapid Start

These are the only fluorescent lamps that are recommended

to be electrically dimmed or flashed. They start as quickly as

the instant-start lamps; require no external starters; and the

ballasts are smaller and more efficient.

Compact Fluorescent Lamps (CFL)

miniature fluorescent lamps; most are now

manufactured with integral ballasts.

High Intensity Discharge Lamps

Produces a very bright light by discharging an arc when electrical current passes

through a metal gas contained under high pressure in a glass bulb;

ballasts and transformer.

most HID requires a _______________

MERCURY VAPOR (MV) LAMPS

Are the first HID lamps to be

developed.

blue-green

MERCURY VAPOR (MV) LAMPS contains mercury vapor in a clear quartz arc tube, which when electrically excited, produces visible light of characteristically ____________

color.

MERCURY VAPOR (MV) LAMPS

Constructed of internal quartz tube enclosed in a bulb; a small amount of

liquid mercury is sealed in an argon gas fill inside the quartz tube.

METAL HALIDE (MH) LAMPS

A modification of the mercury vapor with an arc of improved color.

METAL HALIDE (MH) LAMPS

Improved color rendition without the use of phosphors, and small sources

size.

METAL HALIDE (MH) LAMPS

Life span is shorter than MV.

 32W prod.

MERCURY VAPOR (MV) LAMPS

Longer life span then MH; better lumen maintenance the FL.

METAL HALIDE (MH) LAMPS

A modification of the mercury vapor with an arc of improved color.

METAL HALIDE (MH) LAMPS

It possesses therefore increase light output.

 Improved color rendition without the use of phosphors, and small sources

size.

METAL HALIDE (MH) LAMPS

Life span is shorter than MV.

 32W prod.

HIGH PRESSURE SOMDIUM LAMPS

Contain an internal arc tube made of translucent ceramic material rather

than quartz glass with a small amount of solid metallic sodium and

mercury is sealed in a xenon gas fill.

HIGH PRESSURE SOMDIUM LAMPS

Orange-white and orange-yellow light.

 Commonly used for outdoor application but can be employed in high

ceiling interiors.

HIGH PRESSURE SOMDIUM LAMPS

Longest life span; better efficacy than any other lamp of the same

wattage.

LOW PRESSURE SODIUM LAMPS

 Are blended between HID and FL technologies.

 Constructed of a large sodium-resistant glass tube containing sodium and

neon-argon gas mixture.

 Very low color rendition.

 Orange-yellow light.

 Shorter re-light time compared to HP.

 Efficient lumen maintenance and higher efficacy than MH and MV.

Solid-State Lighting

Refers to a type of lighting that uses light-emitting diodes (LEDS), (OLEDs), or

(PLEDs).

LIGHT EMITTING DIODE

Provides a desired bright, white, colored and long-lasting light. ideal for

retail, feature lighting, ceiling fixture, cove light, etc.

LIGHT EMITTING DIODE

A semiconductor that consists of a chip of semiconducting material treated

to create a structure with two electron-charged materials. when connected

to power source, electrons jump and emits energy in a form of a proton

(light).

RED, WHITE

_______ LEDs are based on aluminum arsenide. _______ light

can be achieved by phosphor coating or by RBG system.

REFLECTOR LAMPS

Are lamp luminaries with built-in reflecting surface used for incandescent, CFL,

HID, or LED.

ELLIPTICAL REFLECTOR

It is an incandescent lamp with an elliptically shaped reflector.

PARABOLIC ALUMINIZED REFLECTOR

May use incandescent, halogen tube, HID, CFL, or LED.

3.1Luminaries (or Lighting Fixtures)

Is the device which supports the source or sources of electric light and redirects or

helps to control the light rays from the source.

DIRECT –

90% - 100% of the light output is directed downwards.

SEMI-DIRECT

60% - 90% of light is directed downwards; while 40% to

10% is directed upwards.

GENERAL DIFFUSE OR DIRECT-INDIRECT

provides approximately

equal distribution of light upwards and downwards.

SEMI-INDIRECT

60% to 90% of the light is directed upwards; 40% to

10% downwards.