Update, whilst testing the Cree R2/Oldham set-up I noticed that the overlong cable used to connect the battery/lamp on test was causing a drop of 0.4 volts at the lamp, this will obviously be rectified to some extent when the standard cable is used.
The question for the electronics experts is, how much does the applied voltage affect the light output, if at all?

May seem a silly question but until now I assumed that the stated input of 3-9 volts was taken care of by the electronic bit and that the output remained constant? 🙂

If the R2 unit has a switch mode power supply which I think it does, it should not be a problem. The only thing that you will be loosing via the cable is power.

For example if the R2 unit is pulling 1A, then you are looking at 0.4W of power loss in the cable (voltage x current), a lot really, if you consider that probably equates to around 40lms of extra light you could have if powering a 1W LED.

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If the R2 unit has a switch mode power supply which I think it does, it should not be a problem. The only thing that you will be loosing via the cable is power.

For example if the R2 unit is pulling 1A, then you are looking at 0.4W of power loss in the cable (voltage x current), a lot really, if you consider that probably equates to around 40lms of extra light you could have if powering a 1W LED.

Thank you Mr Mike, electronics is not my strong point. :lol:

Beware the Oldham switch as well, use a little Vaseline or similar. One of my tests discovered a ridiculous 1.4 ohms at the switch, twiddling it caused the meter to drop to zero. When I used Oldhams 'as is' underground, sometimes my light would appear slightly dim, twiddling the switch caused it to brighten.
Also, Mr Morlock, if you are really interested in my work, there is a sort of running account, warts and all, on the 'other' site.

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Beware the Oldham switch as well, use a little Vaseline or similar. One of my tests discovered a ridiculous 1.4 ohms at the switch, twiddling it caused the meter to drop to zero. When I used Oldhams 'as is' underground, sometimes my light would appear slightly dim, twiddling the switch caused it to brighten.
Also, Mr Morlock, if you are really interested in my work, there is a sort of running account, warts and all, on the 'other' site.

I had to clean and lubricate the switch on my headpiece, probably because it had been open and gathering dust for 30+ years!
I followed up your "other site" thread, impressive bit of research and engineering.
Some of your higher power projects sound like thay may set fire to pit props. 😉

I've added a bit knurling to my alloy extension to aid bezel removal and I may change the glass for lexan to reduce weight (about 3 ounches heavier than standard).

Makes you wonder what price the oriental guys could knock the metal work out for... :glare:

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Makes you wonder what price the oriental guys could knock the metal work out for... :glare:

Couple of quid if they used stamping or die-casting, they could probably file one "out of the solid" cheaper than us. :curse:

Who is winning the lumen output title at the moment with these lamp projects?

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Who is winning the lumen output title at the moment with these lamp projects?

I'm happy at 300 but I think Mr Fellows is going for nothing short of 1000. 😉

1000 Lumens....! with the fitting of heatsinks it may have changed to Watts 😮 :lol:

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I have been using my lamp underground this weekend re-timbering at Frongoch.
I have to say that I am more than pleased; this lamp will run 2 Cree Q5s at 1050 mA each (AMC 7135 drivers) so must be putting out upwards of 450 lumens.
The snap in battery pack is dream and hugs the body very tightly as I designed it to do. On single Cree I can change modes by simply smacking the power pack with the flat of my hand, I don’t have to twiddle the switch on the caplamp.
Surprisingly, although I kept using full power now and again just for fun, I went all day on the same power pack although I had a spare in my pocket. They do seem to last a long time, and I believe that this is a product of the voltage that I decided to run my mainstream lamps on.

The light output is enormous, and I am questioning the desirability of producing one that will power 4 Crees at full power, although I am now committed to doing this just for the fun of it. We could be going into the realms of the ridiculous.

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The light output is enormous, and I am questioning the desirability of producing one that will power 4 Crees at full power, although I am now committed to doing this just for the fun of it. We could be going into the realms of the ridiculous.

Glad to hear your lamp was successful on the field test. 🙂

On test, I had a feeling that my 300 lumen conversion would benefit from a 5 mode R2 unit to allow for situations where full power is not requied.

this thread spurred me on to get out my 35-year-old and quite dead Oldham and look at it again.. but I bottled out and bought one of those Raptor lamps.

nice piece of kit, by the way. Quite impressed with it.

My old Wolf lamp has now become so loose around the shell that the bezel will no longer screw on, and the cable gland nut won't do up in the back.. you can only do so much with Denso!

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Hi Morlock,
If you need any new contacts for your Oldham headset Just PM me, Ive got loads of new ones, Ill post you some up Gratis :thumbsup:

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Hi Morlock,
If you need any new contacts for your Oldham headset Just PM me, Ive got loads of new ones, Ill post you some up Gratis :thumbsup:

PM sent.

Hi All
I am sorry if I am a pain in the bum to those who have read all about this on the mine-explorer site, but there are people on her following this who only use aditnow. At least I think so.

Anyway.

The lamp I have been using as last described continues to function like a dream, however as I have remarked there never seems to be a time when I have to change the power pack. This lamp is also labour intensive and expensive on parts, so this caused me to reconsider the idea of a cheaper compact model.
Another thing about this lamp is that the heat sinking is way more than is actually required, so there is obviously scope to reduce the heat sink area.

What I have done is produce a lamp using a radically different internal design. I have dumped the aluminium reflector unit and mounted my own hybrid circuit board on a copper plate. This screws directly to the leg of the thermal conductor.
I have fitted an integral battery using 4 X 18650 cells. Because I have freed up the positive terminal block inside the lamp, this lamp can be recharged from a standard Oldham through the headset charger. The internal voltage limitation circuits have been tested up to 6.5 volts, so the 5 V of the Oldham charger is well within bounds.

The light output is slightly below that of the model with the front extension as only one emitter is on overdrive, the mode regulatable one is slightly underdriven on the maximum setting, so full power is about 460 lumens.

Battery duration is extimated to be about 4.5 hours on full power, 9.5 hours on single emitter at full power, and 14 to 16 hours with single emitter at 70%, this is the popular setting for general use.

I am calling this lamp the “UniStar” or universal lamp and price of it will be £100 to £125 based on a new Oldham GT headset. I now have 43 new Oldham, expired shelf life military surplus lamps ready to convert.

The lamp that I have been using is too good to dump but will only be produced with helmet mount battery cells that will require a dedicated charger. I be offering this as the “LumenStar”

The “MagnumStar” superlamp is been currently tested, I have some modifications to make to the internal circuitry that will improve efficiency and at the same time I may be able to boost output. I am also reducing the amount of copper in the thermal conductor, but increasing the heatsink area.

[photo]Personal-Album-128-Image-36833[/photo]

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actually I think that's a bit scary, a cap-lamp having a heat-sink bigger than the rectifier on my old Triumph Thunderbird...

I'd be most interested to see pics of the timbering you have been doing. Looking at it with a 'professional' eye, as it were, I do find the support in digs is of a very variable standard, shall we say. Some of it is very good, especially work done by blokes with past experience and then again, some of it isn't.

I saw some shots from NAMHO taken in Magpie Sough, of people crossing a rotten false floor by walking only on the rails.... :surrender:

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.. be even more scary without it

There are some pictures of my timbering at Talybont under that mine.
I will get some pictures of Frongoch up as soon as I can take some.

There is also a 'secret' dig I am on, there will of course be some pictures etc when its finished.

I agree your comments re "variable standard", when the thing falls in within the same year it was put in, it makes you wonder.

EDIT
Sorry, see "Alltycrib" not Talybont

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just looking there.... interesting stuff.

ttxela makes some pointed remarks at times about this, along the lines that I am used to (a) having resources which cavers and MEs don't and (b) being required to justify the result to HMIM, which cavers also don't have to do, and I suppose he's right :smartass:

use of scaffold poles as supports is a particular aversion of mine... :blink:

some mine timbering can be pretty short-lived, indefinite support of mined-out areas isn't often a requirement after all. Ground pressure from ongoing movement will sometimes destroy any timbering in quite short periods, and this is simply allowed for.

Even backfill stoping methods often incorporate predicted movements, the aim being to contain and manage a progressive, partial collapse of worked-out areas, rather than eliminate it entirely.

even allowing for cost and availability of timber, and the HSE implications inherent in the method, large-scale timberwork like the Great Stull in Dolcoath would never be attempted today

it's bad enough trying to get a simple, traditional timber heading accepted by the Client these days, because of the variables in the calculations.. ::)

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Hi Roy

How's the project going? Any closer to production?

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