Optical_types Emergency_vehicle_lighting

1 optical types

1.1 steady burning
1.2 rotating light
1.3 strobe lights
1.4 led lighting
1.5 modification of stock lighting
1.6 information matrix signs

optical types

the optical , mechanical characteristics of lights used can have significant effect on of vehicle , how readily gains attention in emergencies.

steady burning

the simplest form of lighting steadily burning lamp. these may white lights used on scene enable emergency workers see doing, or may colored lights advertise emergency vehicle’s presence. in latter case, steadily burning lights used alongside rotating or flashing lights rather on own, though historically emergency vehicles displayed steadily burning lights. example, california vehicle code section 25252 states: “every authorized emergency vehicle shall equipped @ least 1 steady burning red warning lamp visible @ least 1,000 feet front of vehicle”

rotating light

the parts , workings of rotating light: top assembled beacon, including optional mirror used when beacon placed in windshield or rear window. center beacon, mirror removed. bottom left , right green dome of beacon has been removed show rotating reflector, stationary incandescent lamp, , electric motor.

these revolving lights may contain single, stationary bulb around curved mirror spun (or attached spinning mirror), or lamp fresnel lens. creates rotating beam(s) of light, appearing flash when viewed. larger rotating lights may contain modular or sealed-beam lamps rotate assembly (commonly 2 or 4 bulbs, possibly 1 or 3).

to protect workings of beacon, plastic dome covers assembly. these domes come in solid colors, in cases front , halves of dome different colors. other beacons use clear dome colored lenses on each lamp. in last case, these rotating beacons referred colloquially ‘gumball machines’ or ‘cherry tops’ in case of red lights.

rotating lights use quartz-halogen or conventional incandescent bulb, though rotating beacons made leds rather bulbs.

rotating lights may used in lightbars in single beacons. in modern enclosed lightbar, ‘v’- or diamond-shaped mirrors provided between lamps give effect of multiple flashing lights.

strobe lights

some emergency lighting based on strobe lights similar used in flash photography. these xenon flash lamps put out brief bright flash discharging large current through gas ionizes gas. light produced has bluish emission spectrum, makes red lightbars glow fuchsia-pink color when lit.

led lighting

police cars sit @ base of i-35w bridge collapse. lightbars mounted on cars led-based. illuminated back-up lamps seen in 2 cars in foreground being used emergency lights operate on different circuit, rather burning steadily indicate cars in reverse gear.



led-lights on volkswagen transporter-ambulance

led-based lighting becoming popular in emergency services several reasons. light-emitting diodes small, solid state, power-efficient, long-lasting (as have no filaments burn out) , can seen @ great distances , in sunlight.

whether lightbars or single beacons, led-based lights typically use clear, colorless dome because light color intrinsic property of leds themselves. led-based lightbars can made thin, reducing wind resistance around 8-10 percent, or made flat , used in novel applications, example flip under sun visor.

led lights used in mode similar conventional strobe lights, can programmed wider variety of flash patterns because of ability switched directly electronics, opposed discharging capacitor through gas-filled tube.

led lights produce relatively little heat when in use. in colder inclement climates, has resulted in led emergency vehicle warning lights (as traffic lights) being obscured buildup of frost or snow, raising safety concerns. solutions being researched provide heat source, necessary in weather conditions, keep led lights clear of snow , frost.

modification of stock lighting

a hide-away strobe light fitted headlamp. strobe light coiled glass tube in bottom of headlight assembly, near center of highlighted region of picture (click picture enlarge).

the vehicle’s stock lighting may modified add flashing , strobe effects. can done adding electronics existing lighting system (for instance, create wig-wag), or drilling holes in reflectors of stock lighting , inserting flashing lights in holes.

information matrix signs

led information matrix sign on police car of national police of ecuador.

some emergency vehicles use signs made of large number of light sources (usually leds), can programmed display messages other road users. can used request other vehicles pull over, indicate special instruction, or display name of operating service (e.g. ‘police’).