EMERGENCY LIGHTS
https://www.elprocus.com/what-is-an-emergency-light-circuit-diagram-its-working/
https://www.homemade-circuits.com/how-to-make-efficient-led-emergency/
https://www.scribd.com/doc/94629911/Automatic-LED-Emergency-Light-Circuit
https://aimlite.com/emergency-lighting-principles-safety-and-security-on-the-path-of-egress/
https://hyclassproject.com/topics/design-and-construction-of-smart-street-lighting-system-usingultrasonic-sensor.html
https://hyclassproject.com/design-and-construction-of-an-automatic-emergency-lighting-system.html
1) How to make Automatic Emergency Light
1.1) Principle of automatic emergency light circuit
1.2) Automatic Emergency Light circuit
1.2.1) Circuit Components
1.3) Automatic Emergency Light Circuit description
1.4) Procedure to implement the Automatic Emergency Light circuit
1.5) Advantages of Automatic Emergency Light system
2) Application of Automatic Emergency Light Circuit
How to make Automatic Emergency Light
In this article you will learn that how to make your own automatic emergency light circuit
with light sensing feature. The circuit is very helpful as it does charges the battery from
the AC main supply and gives the output supply only when there is no ac power supply.
The LED emergency will last long more than 8 hours.
There are three mode of switches in our circuit. The traditional on/off switch is a simple
switch which we use in our everyday appliances. A relay is used in the circuit in order to
sense the ac main supply and will keep the lamp in off mode. An LDR (Light Dependent
Resistor) is used to sense the light and turn on/off the lamp according to.
Principle of automatic emergency light circuit
Automatic Emergency Light block diagram
When there is an ac power supply, the battery charges through the rectifier made up of
diodes meanwhile the LEDs will not glow as Relay sensed the ac power supply. At the
same time the LEDs will also glow as the LDR senses no light. When the Ac power
supply is stopped the LEDs will start glowing if there is no presence of light sensed by
the LDR.
The LDR (Light Dependent Resistor) is present in light, its resistance value becomes
very low and as the result the transistor value (which has the base current from the
LDR) becomes high and so the LEDs. When the circuit is placed in the dark i.e the LDR
senses no light then it has a very high resistance in mega ohms order. In this case the
base current of the transistor is very low which causes the LEDs to turn ON.
Automatic Emergency Light circuit
Automatic Emergency Light Circuit
Circuit Components
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12v Step Down Transformer
Diodes (or a diode bridge)
7809 Voltage regulator
LDR (Light dependent Resistor) 2 Mega ohms
SPDT relay
9V battery 9Ah
Transistor (BC548)
8 High brightness LED (3v, 15mA)
A color LED (for current indicator)
Resistors (10k, 1k, 10 ohms)
Automatic Emergency Light Circuit description
In the circuit step down transformer is used to convert the AC 220V input power supply
into 12v. The diode bridge is then used to convert that 12v ac output from the
transformer into 12v dc output. After converting this 12v into dc there are some variable
(Repel) characteristics in the voltage which is then minimised by using the capacitor of
470 microfarad. The LED connected after the capacitor is used for the indication of the
current flowing through the circuit where as the corresponding resistance is used to
prevent the tiny LED from the 12v high voltage.
Automatic Emergency Light
The 7809 voltage regulator is used to regulate the 12v up to the 9v which is suitable in
order to charge our 9v battery. The IC has a built in current limiting circuit and a heat
sink which helps it to withstand high current as well.
The 6 high glowing LEDs are connected in such a way that may save our power. The
two pair of LEDs are connected in series and the three arrays having LEDs in series are
connected in parallel. For each LED we had used required minimum of 3.6 V and 20 mA
in order to glow in full brightness.
The Relay is used to detect the AC power supply, the choke terminals of the relay are
connected to the outputs of the rectifier. And the output switch is connected in between
the positive end of the battery and the LED arrays.
Similarly the LDR and Transistor setup is connected in parallel to the relay switch in
between the positive end of the battery and the LED array in order to act as a photoswitch. Along with the two switching setup a simple switch is connected in parallel so
that the LED light could be turned on manually as well.
Procedure to implement the Automatic Emergency Light
circuit
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Connects the components as per the circuit diagram shown.
While making connections make sure that there is no connection in between AC and DC end
of the circuit or else it’s going to blow everything off.
Keep the switch at the On position and Give the AC main supply to the circuit, you will be
able to see the battery is charging and the LEDs are not glowing. Now turn off the AC main
supply and you will be able to see the LEDs are glowing.
Now power off the AC supply, keep the switch on and keep your circuit in the light, you will
see that the LEDs are not glowing, take the circuit in the dark and your LEDs will be glowing.
You may like to see Motion detector circuit
Advantages of Automatic Emergency Light system
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Automatic Emergency Light is a very simple setup and could be implemented very easily.
Components used in Automatic Emergency Light circuit are very easily available and at very
cheaper cost.
It is very good choice when it comes to saving energy.
Application of Automatic Emergency Light Circuit
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Automatic Emergency Light Circuit could be used in places where light gets on automatically
as the power goes off.
It could be used as an emergency lamp in homes and other places.
It could be used in study rooms and workplaces in order to avoid sudden power failures.
Automatic Emergency Light Circuit with battery charger is very helpful as a backup power
supply.
https://www.instructables.com/How-to-Repair-ChineseEmergency-Lights/
https://www.emergencylights.net/blogs/productknowledge/batteries-for-emergency-lights-and-exit-signs
BATTERIES FOR EMERGENCY LIGHTS AND EXIT SIGNS
Wed, Sep 18, 2019
By: EmergencyLights Admin
BATTERIES FOR EMERGENCY LIGHT
All emergency lights and lighted emergency exit signs use a battery for powering the lamps. In
order to insure continuous readiness and operation of the emergency light, these batteries are
rechargeable. Circuitry within the emergency light both charges the battery and insures tha t it
stays charged.
TYPES OF BATTERIES USED IN EMERGENCY LIGHTS
There are two types of batteries that are used for emergency lights; they are:
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Sealed lead-acid batteries (the same type used in cars)
Nickel-cadmium batteries
Sealed lead-acid batteries are the oldest rechargeable technology available. They are called
lead-acid because they contain lead alloy plates, immersed in acid. The acid breaks down the
plates, producing the charged electrons which are electricity. More recently, technology of lead acid batteries has improved, allowing for fully sealed units, that don’t require the addition of
water to maintain the acid level.
VIEW OUR SELECTION OF EMERGENCY LIGHT BATTERIES
Nickel-cadmium batteries were the first ever “dry” (no acid required) rechargeable batteries.
Since then, other technologies have been developed, but they are generally more costly. In a
nickel-cadmium battery, the two metals are separated by a dielectric (non-conductive) layer,
causing the metals to magnetically react with each other, producing the charged electrons that
form electricity.
WHICH IS BETTER?
There are advantages and disadvantages of both types of rechargeable batteries used in
emergency lighting fixtures.
Typically, lead-acid batteries are used in steel enclosure emergency lights and nickel -cadmium
batteries are used in thermoplastic housing emergency lights.
It is important to note that in the case of battery replacement, the same type of battery must be
used as the unit originally contained. Changing battery types also requires changing the circuit
board, as the charging circuit is contained on the circuit board.
BATTERY VOLTAGE
Batteries used in emergency lights also come in a variety of voltages, from 6 VDC to 24 VDC.
Higher voltages allow for brighter lamps to be connected to the emergency lights. They also
work better where a remote lamp-head needs to be attached to an emergency light unit, as there
will be less voltage loss over the line distance. Finally, higher voltage batteries also allow for
higher wattage bulbs, adding another increase in light intensity.
In the case of battery replacement in an emergency light, it is important to insure that the same
battery voltage, as well as the same battery type is installed. Too high a voltage will blow the
lamps, while too low a voltage will cause the lamps to be dim. Additionally, if the battery voltage
and circuit card voltage are not the same, the battery will not charge properly.
BATTERIES ARE JUST ABOUT THE MOST IMPORTANT COMPONENT
OF AN EMERGENCY LIGHT FIXTURE BESIDES THE LIGHT ITSELF.
SAFELY SECURED INSIDE THE UNIT, IT IS THE POWER SOURCE FOR
THE EMERGENCY LIGHT WHEN HOUSE POWER IS CUT OFF, GIVING
OCCUPANTS SUFFICIENT ILLUMINATION TO FIND THEIR WAY TO THE
CLOSEST EXIT POINTS.
Before replacing the battery of an emergency light, make sure to first note the type, voltage and
amperage of the old battery. The standard internal power source for most lights is sealed lead
acid and Nickel Cadmium, with very few exceptions. Sealed lead acid batteries have been in use
for the past 30 years, though Nickel Cadmium batteries are fast replacing lead because of their
longer lifespan and compact size.
Emergency Light Batteries come in a variety of shapes and sizes. The 6 volt 4.5 amp sealed
lead acid battery is one of the most common models found in emergency light fixtures. It is
affordably priced and can ship today.
We carry all different shapes, sizes, and models of emergency light batteries and are happy to
answer any related questions you might have. Call us today to place an order or to learn more
about our battery selection. You can also email our battery specialists for information and to
request a quote or invoice.
Without the right battery installed, emergency lights will not function correctly in a dangerous
situation like a fire, earthquake or other scenarios when building AC power is lost. OSHA
(Occupational Safety and Health Administration) guidelines require scheduled preventative
maintenance to insure the units will work during a power outage.
EMERGENCY LIGHT BATTERIES:
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Power lamp heads during an emergency
Must last for at least 90 minutes
Affordable and easy to replace
Available in different voltages and amperages
Tested monthly and annually per OSHA regulations
Battery test buttons come standard on all emergency lights. By pressing the test button, the
emergency light unit switches from AC power to emergency battery power, allowing you to
clearly see the remaining charge.
A fully charged battery in good condition should power an emergency light for at least 90
minutes as mandated by UL (Underwriters Laboratories). If the battery cannot last for 90
minutes, it must be replaced. The UL 924 Listing is only featured on batteries that meet or
exceed UL's rigorous testing procedures.
Many of today's emergency light fixtures come with a self-testing option that allows the unit to
run monthly and yearly checks automatically, reducing the need for maintenance and improving
the efficiency of a buildings emergency lighting system.
Replacing them is also a very important thing to know how to do...
SO WHEN SHOULD I REPLACE AN EMERGENCY LIGHT BATTERY?
Per OSHA guidelines emergency light owners should perform regular scheduled maintenance at
monthly and annual intervals. If either the 90-second or 90-minute emergency readiness tests
prove unsatisfactory (i.e. the lamps don't light up) replacing your emergency light
batteries may be required.
Luckily the maintenance involved is actually very quick and simple, as most modern luminaries
have a push-to-test switch that gives you an accurate battery reading. Pressing this test button
activates the device's cutoff circuits (simulating a loss in AC electrical power) and should trip the
battery. If the battery is dead, the lamps do not come on. It's really that simple.
REPLACING YOUR EMERGENCY LIGHT BATTERIES - STEP BY STEP
STEP 1 - Take a screwdriver and open up the housing. Most emergency lights will take a philips
head head, though some hazardous location of vandal proof luminaire's will use a special hex
driver bit. Hopefully you or your maintenance department kept the included bit when the device
was purchased.
STEP 2 - Now that you have removed the plate you will be presented with lots of wires (don't
worry its normal). Some of these red, black, blue or white electrical wires will lead from the AC
electrical conduit to a voltage transfomer that leads to the switching circuits. One, two or several
wires connect the circuit board to the battery.
STEP 3 - Depending on you emergency light, the battery will either be a sealed lead
acid (SLA) or Nickel Cadmium (NiCd) battery type. SLA's tend to look like baby car batteries,
while NiCd usually resemble normal household AAA batteries, sealed in a protective plastic
shrink wrap.
Most batteries will slide out of the unit once the leads have been removed from
the + and - contact points. Some cells will be housed in a harness, which you must also remove.
IDENTIFYING THE RIGHT REPLACEMENT BATTERY
Remove the harness and battery from the housing. The first thing to note is the voltage which is
typically 6v or 12v. Never try to use a 12V cell in a 6V emergency light, or vice-versa.
ONE OF THE QUICKEST WAY TO FIND THE BATTERY TYPE IS TO SIMPLY LOOK AT
THE LABELS INSIDE THE HOUSING. ON THIS WET LOCATION EMERGENCY LIGHT, IT
READS:
"REPLACE WITH JIMING TYPE: JM-6M10.0AC"
A quick Google search should tell you this is a battery manufactured by NingBo Jiming Electric
Appliance Company. They likely have several US distributors around North America that you can
readily purchase from. Simply place an order and the battery is at your door in two weeks.
However, if no discernible battery type is specified, or if you wish to cross over to an American
brand, call a certified distributor like Emergency Lights Co.
Before making the call, be sure to to identify your dead battery's voltage (6V or 12V),
dimensions (Length x Width x Height in inches) and terminal type to source a new battery. But
wait, you say, what the heck is a terminal type?
IDENTIFYING BATTERY TERMINAL TYPE
SEALED LEAD ACID (SLA)
Faston Tabs(pictured) are the most common terminal for this battery. Your luminaire will be
supplied with a red, black and white blade connectors which slip over these tabs to close the
circuit.
L terminals are found on some larger batteries. They have an L-shaped post with a bolt hole on
the vertical side. These most resemble car battery terminals, so they are incredibly rare unless
they are heavy duty types rated for extended emergency runtimes.
NICKEL CADMIUM (NICD)
Female-to-Male battery leads are easy snap-in bullet connectors that make wiring multiple
NiCd cells quick and simple. Since each battery in the pack has its own positive and negative
terminals, multiple cells are combined into one easy to connect lead.
TYPES OF EXIT SIGN BATTERIES
OVERVIEW
Most emergency Exit Signs are powered by a building's AC power which keeps the battery
backup system fully charged. During a power failure the battery will need to light the sign for at
least 90 minutes. But did you know Exit Signs use more than one type of battery? This article we
will delve further into the types of batteries used in these life-saving signs.
VIEW OUR EXIT SIGN BATTERIES
Some Exit Signs on the market do not require power, however, they are often confused with our
electric LED models. Such non-electric fixtures include Photoluminescent (glow in the dark) and
Self-Luminous signs, which are naturally illuminated by a glowing hydrogen gas called tritium.
Such battery-free units are perfect for remote locations where a building's electricity is not
readily available and have a 20-year operational life; far longer than the 90 minutes provided by
electrical units.
Long ago, Exit Signs were not even considered emergency fixtures, expiring the second a power
loss occurred. Later, buildings began installing battery units on each floor to power a string of
remote Exit Signs. While a major advance from the prior generation, these early emergency
units suffered from an overloaded power-source that would drain to quickly after a power failure.
Today laws and technology have advanced considerably. The incandescent bulbs of the last
century, which might last two years, have been phased out by LED technology that lasts a
decade and uses a fraction of the wattage. Modern Exit Signs also have smaller batteries that fit
within the unit. These combined advantages lead to a more efficient, longer lasting sign.
Nickel Cadmium (NiCad) emergency light batteries are popular for their compact size and
powerful capacities. It is affordably priced and can ship today.
EXIT SIGN BATTERY TYPES
Only three types of battery cells are used in modern Exit Signs: nickel cadmium (NiCad), nickel
metal hydride (NiMH) and sealed lead-acid. Nickel cadmium batteries can last up to ten years
and come in various sizes and capacities to fit different requirements. They resemble small
black bricks with contact points on the front and sides.
Nickel hydride cells appear to be the same as nickel cadmium batteries, only smaller. That i s
because the only major difference in NiMH design are its negative contact points, made of a
hydrogen-absorbing allow rather than cadmium.
Sealed lead-acid batteries are found in most pre-LED exit technologies and current Exit Sign
Combo units. Despite their age, sealed lead-acid can carry a heavier electric load than NiCad or
NiMH, making them ideal for Combo units which include powerful dual headlamps on top of the
standard LED exit design.
Knowing a little bit about battery requirements for the various emergency exit signs will make
purchasing replacements much easier in the future.
CONCLUSION
Replacing your own batteries may sound like a job for the electrician or maintenance man. But
as you see it is actually pretty simple stuff! It requires ZERO knowl edge of electricity or wiring
and does not require a certified electrician to install.