royfellows
14 years ago
A customer has brought in a Birchley Products divers lamp for conversion to LED. This was a relatively simple job as I had already used the methodology in a conversion of a Maglite head to a photo lamp.
The original power source was a cluster of 10 X 1.2V NiCads giving a working voltage of 12V. After some deliberation I removed these as the voltage was not suitable for what I wanted to fit, being 4 X Cree XM-L at 2,5 amps giving 3200 lumens.
The original 12V supply would have had to have been mated to either 3 or 6, I elected to use 6 2500 mAh Li Ion Trusties wired 2 in series X 3 parallel to give 8 volts. The LEDs being connected X2 in series to 2 drivers.

The drivers used were the SKU 20330 drivers from dealextreme. As they came the main diodes were 3 amp, NOT 2 amp as incorrectly posted on the DX website. However, as I found it impossible to direct heat sink them in my normal way I uprated these to some real heavy duty 5 amp jobs from Farnell, OK if the form factor isn’t a problem. Quite an overkill but they don’t even seem to get warm now.

🔗Personal-Album-128-Image-64003[linkphoto]Personal-Album-128-Image-64003[/linkphoto][/link]

The key to heat dissipation is the big copper ‘ears’ as can be seen in the picture, inserting this into the aluminium lamp body gives a good thermal contact, just the same way as in the Maglite head conversion I did.
The little yellow plug is for recharging using the customers Trigon charger, balance lead to metal of old charging plug.

🔗Personal-Album-128-Image-64002[linkphoto]Personal-Album-128-Image-64002[/linkphoto][/link]

I was disappointed that I could not use 4 of the big reflectors due to lack of space, so used 2 of these plus 2 small ones. These were assembled by the use of epoxy adhesive while standing on a flat surface. Do not fit reflectors to the LEDs separately as you will get separate beams going everywhere.

🔗Personal-Album-128-Image-64001[linkphoto]Personal-Album-128-Image-64001[/linkphoto][/link]

🔗Personal-Album-128-Image-64004[linkphoto]Personal-Album-128-Image-64004[/linkphoto][/link]

🔗Personal-Album-128-Image-64000[linkphoto]Personal-Album-128-Image-64000[/linkphoto][/link]
My avatar is a poor likeness.
royfellows
14 years ago
Sorry gang, I should have mentioned the diode is of course a Schottky, I measured the Vf drop at 0.33V.
My avatar is a poor likeness.

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