simple high efficiency lighting for self assembly

7/31/2019 Simple High Efficiency Lighting for Self Assembly

1/17

Quite Light for a Loud World -- Page 1

Instructions for building a low voltage high efficiency EyeFriendly Sky Friendly Lighting System for pathways, docks,gates, roadways, driveways, homes, businesses or anywhere wheresafe voltage or soft - high efficiency lighting is desired. By Mark J. Carter

These instructions will show you how to build an efficient lighting system that can save you a lotof money and make your night time environment more eye and sky friendly.

This system will allow you to bring some quite light into your life while using only a fraction ofthe power of conventional lighting.

It can be made as a solar powered or plug in system.

This lighting method will significantly reduce the electric load on a solar power system; or yourpocketbook if you are using generators or purchasing electricity.

The light cast in the general illumination assemblies used for pathways, docks, hallways, rooms,garages, and other areas will be bright enough to see obstacles in the path while preserving yourability to observe the sky and your surroundings. The reading assemblies will present enoughlight to comfortably read by.

Two assemblies can illuminate a car port bright enough to avoid tripping hazards.

It will take about 4 LEDs (equivalent to 2 assemblies) to make a usable reading light.

These instructions will also show you how to build a photo-sensitive switch that canautomatically turn the lights on at dusk and off at dawn. This is a critical function for a solarpowered system and prevents wasting energy in a plug in system.

This lighting system takes advantage of modern high efficiency low voltage LEDs; the mostcommon light colors being White, Blue, Green, and Red.

This type of lighting system uses about of one watt for each 2- LED assembly. The system thatilluminates my sidewalk and drive way uses 7 assemblies and effectively illuminates about 80linear feet. Thats about 3 and one half of watts of power.

The LEDs should last some number of years for dusk to dawn lighting.

This type of lighting system is very simple to assemble; however, for the best outcome somebasic tools are needed. I recommend the following tools. Wire strippers, wire cutter, solder gun, adrill with a 13/64 drill bit, a hack saw, scissors, some electrical tape, and an (optional)inexpensive Volt Ohm Meter.

The system was originally designed to be powered by a small 20 watt solar panel charging a carbattery. Plug in systems are not as efficient because of the converter loses; but use significantlyless power than store bought high efficiency lighting.

For a plug in system, a regulated 6 volt or 12 volt AC - DC converter is required. Other voltages


2/17


can be adapted but are not recommended. I purchases some ideal 6 volt DC - 1.5 amp powersupplies from http://allelectronics.com/. The converter should be rated at 6 or more watts. For a12 volt DC Power Supply this means the current rating should be at least 500 mA (.5 amp) and 1amp for a 6 volt converter. This is sufficient to easily support up to 12 2 LED light assemblieswithout bringing the power supply to near full capacity. Ten assemblies will easily light 100 -200 feet of pathway or dock way. When ordering make sure the power supplies are adaptable to

your supply voltage. If in doubt ask the supplier by contacting them through their website contactmethod.

I have also purchased a variable voltage regulated AC - DC power supply at the electronics storein Savaii so I know they are available. I also saw two models at an electronics store in Apia; but Irecommend ordering them with your LEDs.

It might be possible to scavenge the AC - DC Converter; but the converter must be the correctvoltage. A converter may be scavenged from any type of electronic charging device used fortoys, rechargeable flashlights, mobile phones, or any other type of device as long as they meetthe minimum power requirements as described above and supply a regulated voltage. It is alwaysbetter if the maximum current rating of your converter supply exceeds the demand of yoursystem by a substantial amount. This reduces thermal losses and increases the overall efficiencyof the system.

Above is a picture of a common multi-voltage converter I purchased at the computer store inSavaii. It is rated at 1 amp at 6 volts and .7 amp at 12 volts which would easily support twentyseries 2- LED-127 assemblies. When properly mounted and pointed this should illuminate about


3/17


2000 square feet at light levels that would allow seeing tripping hazards or critters in the path.When lighting pathways this would support a system supplying illumination for about 200 to 400feet while consuming less than 10 watts of power including converter and resistive losses.

Other Things you will need to build the basic system:

1. High Efficiency LEDs that can be ordered and shipped by http://allelectronics.com/.Your choice of LEDs will be the most important part of building your lighting system.

Because shipping costs vary worldwide. You will need to contact them via the email addressfound on their website and agree to a shipping cost. I have mine sent via the US mail. Checkwith your local postal service to determine whether mail can be received from the US or if otherforms of shipping are available.

The data sheets available at this web site should give you information needed to find othersuppliers if needed.

I use flanged LEDs to make it easy to mount them on any thin surface.

For white LEDs, which I have found to be the most energy efficient and brightest, I use thehttp://allelectronics.com/Part number LED-127.

For green I use part number LED-57, for Blue I use Part Number LED-74, and for Red I use PartNumber LED-126.

Important Note: The red LEDs are rated at a lower voltage and should not be used unless youare using a lower voltage power supply, or use three LEDs to an assembly, or willing to wastepower by using current limiting resistors. I do not recommend these LEDs.

2. Electronic solder for soldering the two LEDs in series for each assembly and soldering thehookup lead wires to the LEDs. I have seen plumbing solder sold near the soldering irons insome of the hardware stores. Make sure you use electronics solder. It can be ordered with theparts.

3. A simple switch about any type will work. If the outlet that the power supply will beplugged into has a switch then that will work without alteration.

4. A fuse that has a current rating is just a bit above the circuit current but always below therating of your transformer. The fuse and fuse holders can be ordered at http://allelectronics.com/. The circuit current can be calculated as P*N / V where P = the power draw of each assembly, N= the number of assemblies, and V is the supply voltage. The power of a single 2 - LED assembly

made from white All Electronics Part number LED-127 is about 40 mA when powered at 6volts. This is .04 amp. Ten assemblies should draw somewhere around 400 mA and can beprotected with a .5 amp or 500 mA fuse. I have been using 1 amp fuses which may be risking theLEDs in the case of a supply wire direct short; but it protects the 6 volt - 1.5 amp power supply.Dont allow a direct short between the Positive and Negative supply wires and your LEDs wont

be put a risk. NEVER OPERATE A LIGHTING CIRCUIT WITHOUT A PROPER FUSE.

5. Something to mount the LEDs in; I use inch PVC 40 end caps; but about anything you


4/17


can drill a hole in will work. This includes bamboo, wood, coconut shell or any other thinmaterial.

6. Electrical Tape: To insulate bare wires.

7. Good Quality wire. In the US I used size 18 - 2 solid copper conductor thermostat wire.

Other types of wire can be used but remember that the wire adds resistance to the circuit. Thesmaller the diameter of the wire and the longer the run of the wire the more resistance the wireadds to the circuit. I use the same wire to make my hookup wires and lead extensions.

8. Wire Nuts: If available and properly sized for the size of wire you are using.

The instructions for building a automatic on at dusk / off at dawn switching system (AutomaticControl Box - A.C.B.) is covered later in these instructions. The use of the A.C.B. is highlyrecommended to avoid leaving the lights on during the day. It is not difficult to make.

All components can be ordered on line if needed. If you have difficulty obtaining the neededcomponents then send me an email at [email protected] and I will assist you.

I have found that the wire is the most difficult thing to obtain. You may have to special order thewire from the hardware supplier or on line. Any size wire greater than #20 would probably workbut the bigger the wire the more expensive and difficult it becomes to work with. Again I haveused solid copper conductor #18-2 thermostat wire and it works great.

Fabricating the light assemblies:


5/17


A. = Is a single LED. In nearly all LEDs I have worked with the positive lead (wire) is longerthan the negative lead. If in doubt test the LED by using two double AA batteries connected endto end.[+ -] [+ -] This is a series connection and the voltages of the two AA batteries sum. A singlebattery is 1.5 volts so two in series is 3 volts. You will not hurt the recommended LEDs if you

attempt to connect it backwards as long as the voltage does not exceed 3 volts. The LED simplywill not light until you correct the polarity. (Do not use with Red LEDs.)

B. = Shows two LEDs soldered together in series. This means that the negative (short) lead ofthe first LED is soldered to the positive (long) lead of the second LED. When two LEDs aresoldered in series the operating voltage of the two LED assembly becomes two times theoperating voltage of a single LED. Two 3 volt LEDs in series as shown - now operate from a 6volt source. If you were to use a volt meter to measure the voltage across each LED you will findthat there will be a 3 volt drop across each one when a 6 volt supply is used.

C.= Shows two wires soldered to the assembly. These hook up wires (leads) allow adequatelength to mount the assembly inside a holder. The length of the hook up wires will depend on thetype of holder you choose to use.

D. = This shows all of the bare wire ends in the assembly wrapped in electrical tape. This isimportant to prevent shorting out the assembly which can happen if one bare wire touches

another. The electrical tape will prevent the wires from touching each other. Make sure you

clearly mark the positive and negative hook up wires of the assemblies for reference when

wiring them into the lighting circuit.

E. = Once the LEDs are soldered together they will need to be mounted in some type of holder.For the recommended LEDs I use a 13/64 inch drill bit to drill the mounting holes. I use inchPVC End Caps as holders, but you can mount them in any thin material. You can put them in

coconut shell, bamboo, or even mount them in a sculpture. You have imagination - use it!!

Once the LEDs are placed inside the holder put a spot of glue on the very outside edge of theLED and allow it to dry. Do not get glue on the LED face.

Mounting the LEDs in a holder that can be pointed is very useful, as described later.

When making the assemblies, test each 2- LED assembly with a 6 volt supply as they are made.You can test each assembly using your 6 volt power supply or by making a 6 volt supply fromscavenged battery holders. (Use a 4.5 volt supply for Red assemblies)

Use a single LED or a 2- LED assembly to experiment with to determine how you will illuminate

any given area. Simply take a single LED or a 2 - LED Assembly (preferred) with a proper testsource voltage to the area to be illuminated, extinguish any existing illumination, and experimentby pointing the light from different locations and angles. You will be surprised how much lightyou can create with the recommended small, low power LEDs . A reminder, use a 3 volt sourcefor a single LED and a 6 volt source for a series 2- LED assembly. (2.2 V or 4.5 V for Red)

Two 6 Volt Assemblies ( 2 LEDs in each assembly) wired in series will operated from a 12 voltsource. (3 volts + 3 volts) + (3 volts + 3 volts) = 12 volts. This is explained in more detail later.


6/17


LEDs can be ruined by excessive voltage so never apply a voltage greater than what they aredesigned to operate at. Good quality LEDs will survive slightly higher voltages than the ratedvoltage but it will reduce their life span. Too high of a voltage and you will ruin the LED.

If you choose to paint your holders and other components, do so before mounting the LEDs.

Making an assembly that can be pointed:

The above chicken scratching shows an assembly that can be aimed or pointed in both thevertical and horizontal direction. Each LED has a beam width of about 15 degrees. The furtheraway the assembly is mounted from the target area the greater the area of coverage. A singlewhite 2- LED - 127 assembly will adequately illuminate 10 to 20 feet of pathway to a width ofabout 7 feet or so. If it is not practical to mount the first assembly far enough away of the targetarea, then the light assembly can be pointed to light an area further away from the assembly

while another more distant assembly is used to illuminate the area near the first assembly.Another method is to mount the light near the ground and graze the light down the pathway.

Other methods and holders can be used as Point-able Assemblies. Use your imagination! Anassembly mounted in a coconut shell can be pointed. You can make the assemblies out of justabout anything.


7/17


Wiring the assembly for a 6 volt system:

Using two conductor wire connect each assembly in parallel with the other assemblies. This is

done by cutting the power supply wire near the leads of each assembly. When doing so you willhave a positive end wire from the source, the positive end wire from the assembly, and thepositive end wire of the continuing power supply wire in addition to the three negative ends.

Using a wire nut of proper size for the wire, connect the three positive ends together. Do thesame for the three negative ends.

Fold the connections parallel with the wire and tuck into the conduit and fit the conduit into theT of the assembly.

Although I recommend conduit to protect the wire and mount the assemblies, any mounting andsupporting material can be used including bamboo or any other material that can be split

hollowed and tied or glued back together after the wire has been run. I do not recommend justhanging the wire because of the expense of the wire. It will last much longer if it is somehowprotected from the elements. Running the wire through something also reduces the chance offuture shorts caused by wear of the insulation around the wire.

It is recommended that the conduit be fitted and loosely mounted before running the wire.After the conduit is mounted the wire is run through the conduit and the assemblies wired andthen mounted to the conduit. Running the wire means shoving or pulling the wire through theconduit.


8/17


When operating from a 12 volt source, two assemblies are connected in series. This series branchis then connected in parallel with the other assembly pairs.

Wiring a 12 Volt Assembly:

At the first assembly the positive lead of the assembly is joined with the positive wire of thesupply and the positive of the continuation supply wire; identical to wiring a 6 volt supply. Thenegative supply wire does not need to be cut at this point.

A single wire runner is then connected from the negative lead of the first light assembly to the

positive lead of the second light assembly. Note that between the first and second assembliesthere are three wires. The positive supply wire, the negative supply wire, and the series runner.

Remember; the series runner is connected from the negative lead of the first light assembly to

the positive lead of the second assembly lead.

The negative lead of the second light assembly is then connected to the negative of the supplywire and the continuation supply wire as is done with a 6 volt assembly.

What has been done is that two 6 volt assemblies have been wired in series to make a 12 voltbranch circuit wired in parallel with the 12 volt supply wires. This is done with every two sets ofassemblies. When making a 12 volt system with 6 volt assemblies the total number of assembliesmust be an even number.


9/17


Simple circuit diagrams for both 6 and 12 volt systems are shown below; without an AutomaticControl Box.

The Optional Automatic Control Box:

The Automatic Control Box turns the lights on at dusk and off at dawn. Although this device isnot required to operate the system, it is highly recommended for systems designed to operateoutdoors in order to prevent the lights from operating during the daylight hours. I recommendthat a solar based system not be operated without an Automatic Control Box. It is quite simple tomake.

Building the Automatic On At Dusk / Off At Dawn Control Box:Required components are:

One Photo-Resistor; I ordered mine from http://www.digikey.com/ part number PDV P 8001-ND. This is a 3k-11k Photo-cell.

One common small diode obtainable from any supplier, or scavenged from other electronicdevices.

One P Channel MOSFET transistor; this is a special type of transistor I ordered fromhttp://www.digikey.com/ part number IRF 9510 PBF.


10/17


One small 100 K resistor that can be ordered from any supplier.

A small mounting board that can be ordered from http://allelectronics.com/or made by handusing a drill, a properly sized bit (or point of a nail), and copper tape or small diameter wiremounted on a non-conducting flat material such as plastic.

Some type of small box to mount the automatic system in. A common switch box purchased atthe hardware store is ideal.

Making the Automatic On at Dusk Off at Dawn Control Box:

My pencil scratching (drawing) of the system circuit, P Channel MOSFET, and board layout isshown below.

The Automatic Control Box uses a special type of transistor in combination with a Photo-Cell (or

voltage bias from the positive wire of a solar panel) to turn the lights on at dusk and off at dawn.

This type of transistor is called a P-Channel MOSFET and operates like a normally closedswitch.


11/17


This picture shows the front and back side of identical P-Channel MOSFET transistors.

A: The A terminal is called the Source. It is the terminal that collects the power from the

supply wires.

B: The B terminal is called the Drain. It is the terminal that emits the power to the circuitthat is being turned on or off.

C: The C terminal is called the Gate. This is the terminal that causes the switch to beturned on and off.

In this application this special type of transistor acts like a normally closed (turned on) switchuntil a small current is applied to the Gate at which time the switch is opened (turned off) andshuts off the electricity between the Source and the Drain.

The control box uses a Photo-Cell (Photo-Resistor) to control the current to the Gate. It isconnected between the Source voltage and the Gate. When there is no light striking thephoto-cell the resistance of the photo-cell is very high. This means that there is not enoughcurrent allowed to flow to the Gate to open (turn off) the switch. The transistor switch is on.

When light strikes the photo-cell it greatly reduces the resistance of the photo-cell allowingelectrical current to begin flowing to the Gate which opens (turns off) the switch. Theelectrical current now stops flowing between the Source and the Drain. The transistor switchis off.


12/17


Here is a closer look at the switch circuit.

In this chicken scratching the terminals of the transistor are shown as A, B, and C.

The board can be made from a general purpose electronics board ordered from the same placeyou get your components or a piece of plastic and some small copper wire.

The dots are connection points. This is where wires and components (parts) are connectedtogether using solder. Make sure you use a good quality electronics solder.

Drill (or punch) small holes at the connection points where you can insert the component leads(wires) and hookup wires to.

On one side of your board (plastic) insert the ends of short pieces of thin copper wire that willconnect your components together. In the case of the A and B leads it is possible to solder thesupply positive lead directly to the A-Source terminal and the B-Drain terminal directly to

the positive lead of the lights as shown in the diagram. The Source wire and the Drain do nothave to be big wires but they must be big enough to handle the current. Number 18 or 20 wireshould be sufficient. The connecting wires to the Photo-Cell can be quite small because thiscircuit branch does not carry much current. The same is true for the Gate connection wireswith the diode and resistor.

Make sure the resistor you use is a 100 Kilo-Ohm resistor. Both the resistor and the diode can bequite small as neither of them carry much current. (100,000 OHM resistor)


13/17


You will need to solder small hookup wires to the leads of the photo-cell. Do not connect thephoto-cell to the board until you have mounted the photo-cell to your switch box or whatevertype of box you decide to put the Automatic Control Board into.

Be careful when you solder components that you only touch the leads long enough to deposit asmall bit of solder. An alligator clip used as a heat sink can be used to help carry the heat away

from the component. To much heat for too long and it will ruin the component.

Avoid breathing the fumes from the solder because they are toxic.

Make sure you wear something to protect your eyes from splatter.

Solder guns take a few minutes to warm up. They get VERY hot and will melt and burn throughthings very fast so make sure you have something to set the soldering iron on. BE CAREFUL!You probably cant kill yourself with one but you could certainly cause a bad burn or start a fireif you are careless.

Preparing your control box:

The Photo-cell will be mounted in the control box so look at where you plan to mount yourcontrol box and make sure that the lights from your assemblies, as well as other lights, will notallow light to strike the photo-cell. This is very important because the Photo-cell is quitesensitive.

Consider where to drill or punch access holes into the sides of your container (box) for the inputwires from your DC power supply and your output wires to the light assemblies.

Mounting the Photo-Cell:

Use a 13/64 inch drill bit or other tool and make a hole through your control box container justbig enough to put the face of the photo-cell into. Take a small piece of tape and place the tape on


14/17


the outside of the box and press the face of the photo-cell against the tape so that the tape holdsthe face of the photo-cell in the mounting position. The photo-cell should now be flush (even)with the outside of the control box. Place a small drop of good glue on the back edge of thephoto-cell to hold it in place. Remove the tape once the glue has dried.

Once the glue is dry put the input power supply wires and the output power supply wires through

the access holes into the control box.

Connect the supply input and output wires (or leads ) to the board as shown on the drawing.

Connect the hookup wires of the Photo-cell to the control board as shown in the board layoutdrawing.

Place the control board inside the box (container) carefully folding the wires into the box makingsure that there is no possibility of any bare wires or leads making contact with any othercomponent or wire. (Use electrical tape to insulate bare wires if needed.)

It is recommended that after assembling the control board spray all of it with acrylic or paint toreduce corrosion. Allow to dry completely before applying power to the circuit.

Close up and mount the control box at the desired location.

The 100 Kilo-Ohm resistor. The resistor is a required component for the Automatic ControlBox. Without the high resistance there would be a large amount of current flowing through thegate. The resistor prevents a direct short in the control circuit, allows the Gate to depolarizewhen current is no longer applied to the Gate, and keeps the off state power consumption at anabsolute minimum.


15/17


The Diode: Common diodes require a forward bias of about .6 volts to begin conducting. Theyconduct in only one direction. The stripe of the diode is the negative terminal of the diode. In thisapplication the diode stripe is the end nearest the Gate terminal.

I dont know if the blocking diode is needed for the plug-in circuit; but I have never tested acircuit without one. I originally used it to prevent current from flowing from the Source backthrough the Gate and into the solar panel in a solar application where the voltage from thepositive lead of the solar panel was used in place of a Photo-cell to control the Gate.

All I know is the circuit works well in both plug-in and solar applications.

To test the system: Remember that the photo-cell is very sensitive to light.

Use electrical tape to cover the photo-cell and make sure no light can enter the control boxthrough the access holes. Apply power to the circuit. The lights should come on. If not take adark colored material and cover the entire box in addition to the electrical tape. It takes severalseconds for the resistance to decay in the photo-cell and for the lights to turn on. Remove thetape from the face of the photo-cell and the lights should turn off in daylight.

All of this may appear a little confusing or daunting if you are new to this kind of stuff; but Iassure you - YOU CAN MAKE IT WORK!


16/17


Solar Application:

The above diagram shows a Solar Powered System Circuit.

The Solar Panel is a common 20 watt solar charger designed to charge automobile batteries.

The Solar Charge Controller protects the battery from excessive charge or discharge. The ChargeController normally comes with the solar panel but make sure it does.

The Automatic Control Box is identical to the one described above.

The battery is a good 12 volt car battery.

The lights are wired as a 12 volt system

.This system is designed to support about 10 to 12 2-LED assemblies with a 2 to 3 day reservecapacity for rainy days; and that with the lights on from dusk to dawn. This should supplyminimal light for two small homes in electrically remote areas.

System costs:

LEDs - US $1.50 each plus postage. This is $3 per assembly plus the cost of your mountingmaterial. When using PVC I estimate that cost at about $5 US per assembly. This is expensive


17/17


but so is electricity. Using available coconut shells and bamboo for holders and conduit will keepthe costs at a minimum and probably look nice also.

The Automatic Control Box uses about $5 US in parts. A photo-switch that can be adapted to thisapplication can sometimes be found at the hardware store but at substantially higher cost.

What you use for the box itself is up to you. I recommend a common switch box from thehardware store or a project box that can be ordered on line for about $3.00 US.A 20 watt solar charger for a 12 volt battery costs about $80 US and the battery about $40. Iunderstand that is a lot of money but when electricity costs are this high, and they are going to gohigher, the return on investment comes relatively quickly.

Calculating Electricity Costs:

To calculate the cost of operating a light or other electrical device take the rated powerconsumption in watts, divide it by 1000, and then multiply this by the Kilowatt Hour Cost ofyour electricity. This gives the hourly cost of operation. P/1000 * KWH cost = cost per hour.

Example: In Savaii a 60 watt light costs 60/1000 * .82 = .0492 Tala per hour to operate. If thislight operates 8 hrs per day then the yearly electricity cost for that one bulb is 143.66 Tala peryear.

Using multiple lighting systems of this type that are properly mounted and pointed; 60 wattscould easily and safely illuminate about 1200 feet of walkway to a width of about 5 feet. Thatsabout 6000 square feet. It may not light up the trees and sky; but the path will be safelyilluminated.

I have built and tested 4 systems of this type; including one solar powered system. It works and itworks good.

Use your imagination and share what you learn with others.

Eye Friendly Sky Friendly Lighting Bring some quite light into this world.

simple high efficiency lighting for self assembly

Documents