Hexaspherical

I am slowly catching up with some of my light design ideas.

This one has been inspired from my time out on the local Coastguard SAR boat. At present we are using 150mm 50-100watt halogen spotlights.

These are very disappointing to use for many reasons.

They have a fair amount of spill that falls back on the boat causing disruptions to the crews night vision.
They dont really throw.
They have a terrible colour.

At night when out I will take my modified WF502b that uses a R2 with an aspheric from Ahorton. While it does not quite match the output of the halogens it comes surprisingly close in usefulness.

Anyway I had an aluminium disc lying around and a use sprung to mind.
The pics tell the rest!







I plan on putting a 50-100mm shroud around the LED's to stop annoying spill light from being visable to the crew. The inside of which will be painted black. A acrylic lens on the end will aid in weather proofness.

I will direct drive it with resistors from the boats 12v supply. I will probably add a thermo fuse to half the array so if it over heats at least half will still run. I will start running it at 1 amp each LED and if I have no or little heat issues raise it up a bit.

I am still undecided on the handle. Perhaps pistol grip.

Switch is also undecided. Maybe a toggle and a push hold switch.

haha, damn, that's cool!


beamshots!

That looks like it will be amazing.....

I'm working on a similar project but I'm using smaller 12mm aspherics so it won't throw quite as far.

Looking forward to the beamshots :naughty:

Packhorse...

:twothumbs


I know we all got the news Moby **** was having problems with his sight all the way down @ 100ATM, so nice of you to help out my man!

Your crew are gona love it, keep up the good work old boy.


Kind regards

Cool project. Glad to see you found good solution to your problem.

do you have any beam shots?

i'm also wondering what type of aspherical lens you are using? i am interested in doing the same thing

mds82 said:

i'm also wondering what type of aspherical lens you are using? i am interested in doing the same thing

Click to expand...

Packhorse mentioned he's using an Ahorton aspheric. That's not a type of aspheric lens, but a fellow CPF member.

Very cool project - I like it a lot. Nice photos as well :thumbsup:

At least on my car projects the 12 volts was really 13.5-14.1 volts when the alternator is charging the battery. Do you have the same variation on the SAR boat?

Will

No beam shots yet as the lenses are not mounted.

Yes those are the aspherics. I have found them to be the best for use with XR-E's

Yes the voltage does swing that high on the boat too.
I have heard you can set a voltage regulator to use it as a current regulator. Not very efficient but thats not an issue on the boat. Anyone know how this is done?

Packhorse said:

Yes the voltage does swing that high on the boat too.
I have heard you can set a voltage regulator to use it as a current regulator. Not very efficient but thats not an issue on the boat. Anyone know how this is done?

Click to expand...

Here you go buddy:
http://http://diyaudioprojects.com/Technical/Voltage-Regulator/


As you noted, not the most efficient, but it should work well in your application. Although most regulators will have an automatic shutdown due to heat (and therefore you would not damage it), it would be good to use a good size heatsink on the regulator tab to prevent it from going into thermal shutdown. Basically the power dissipated will be roughtly (Vout - Vin) * Iout, but that web site has a handy calculator as well, which will help you with the necessary wattage for the R1 resistor.

Will

Thanks, thats what I was looking for.

in terms of efficiency it does not seem that bad.

Lets assume a 2 amp load at 13.5 volt. Thats 27watt
Use a 0.62 ohm resistor and you get 2.5 watt heat dissipation from the regulator.

That means an efficiency of 90%. Thats pretty good isnt it?

:twothumbs beamshoot

How far do the existing halogen lights throw?

Before the beamshots arrive, I'll make a prediction about what the beam will be like:

On a clear night, I reckon you'll be able to shine up to 490m away and the beam will be about 44m wide at that length.

This is based on my own experience with the lens, but I've only ever had two going at once.


As for efficiency, whatever you do will still be better than 50-100W of halogen, and you'll have more light.

ahorton said:

How far do the existing halogen lights throw?
.

Click to expand...

Nearly as far as my 2.5yo daughter can throw her brother

Just a note, I have not focused these as sharp as they could be. Reason being that I wanted a wider beam.

Nice work :twothumbs:thumbsup:.

Imagine just 4 P7s/MC-Es with aspherics...16 spots? :huh:

they would warship you if you macgyver'd a focus function into your spotlight

Packhorse said:

Thanks, thats what I was looking for.

in terms of efficiency it does not seem that bad.

Lets assume a 2 amp load at 13.5 volt. Thats 27watt
Use a 0.62 ohm resistor and you get 2.5 watt heat dissipation from the regulator.

That means an efficiency of 90%. Thats pretty good isnt it?

Click to expand...

That is the power lost in the resistor alone, but the regulator will also have some power lost as well depending on differential voltage across the regulator, which in a linear regulator is usually 1-2 volts, depending on the device/design. So if we assume that the input voltage is 13.5V and the the output voltage were 12V:

Preg = (13.5 - 12) * 2 = 3 watts

So the total power loss would be about:

Ploss = Presistor + Preg = 5.5 watts

for an eficciency of:

Efficiency = Pout / Pin = (12V * 2Amp - Ploss ) / 13.5V * 2Amp = (24watts - 5.5 watts) / 27 watts = 69%

This "relatively" lower value is what I meant earlier by these solutions not being very efficient - you loose power on the regulator and on the resistor, and the larger the difference between the input voltage to the output voltage, the higher the losses become.

Then again, since we are using the energy/supply from the boat, and not from a small hand held cell/battery, this is not critical at all in your application, except for the need to select the right wattage for the resistor, and to have enough heatsink for the regulator (to prevent thermal shutdown).

Will

I fired it up tonight .
Pics are pretty poor but there is a couple for comparison.
I am simply blown away but its output.
At this stage I just used a current limiting resistor.

Sorry about the poor quality shots but.....



Hexaspherical R2 driven at 1amp per LED

Quad aspheric Q5 dive light driven at 1400ma per LED

Triple aspheric Q5 dive light driven at 933ma per LED plus MC-E driven at 2.8 amp

HA! found my three legged friend



I call this shot "Why my neighbours hate me"




For comparison 21w HID




my Quad Mag next to a 21w HID.



All shots have same camera settings.

Dude! Those beamshots look awesome! Nice job :twothumbs