50W LEDs

[MichaelG.]

This is just a ‘heads up’ …

I’ve ordered a couple of interesting LEDs on ebay
https://www.ebay.co.uk/itm/294243855666 ... 2906942558

These are ‘warm white’ and, despite living in the U.K. I have ordered 110Volt versions
… I have a preference for the lower voltage, and for running such devices from a ‘safety isolating transformer’
… Something to do with keeping potentially-lethal voltages away from my body !

I will report back in due course.

MichaelG.

[dtsh]

Quite interesting. I wonder if/how bad the flicker will be?

I presume the driver is built in; lifetime and dimmability are my first questions.

[75RR]

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Here is a similar one from amazon with a few more specs and some reviews.

https://www.amazon.com/Tesfish-White-En ... r=8-3&th=1

[MichaelG.]

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That’s a useful link …Thanks

MichaelG.
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Edit: __ and this looks encouraging : https://youtu.be/tKAfRbMJCF0

[Glot]

You can use an isolation training if you like that idea. Doesnt need to be a step down. Isolation trannis have other isolation features. However, they have their fails. They only isolat the device from earth. You will still get an electric shock if you connect to both outputs.
Also, I would be surprised if that LED array is actually 50 watts. Only doing measurements will tell you. I personally use 6 watts in about 5000K and find that ample.
You will also need a massive heat sink if it is anything close to 50 watts.

[MichaelG.]

Thanks for your comments, Glot … but they are largely superfluous my situation.

I am hoping to use LED to replace a powerful tungsten-halogen fibre-optic illuminator.
These particular items may, or may not, turn-out to be suitable
… but they are very reasonably priced, and ‘interesting’

MichaelG.

[Glot]

I use 50 watt LED to light up small car parks. If they are decent qua.ity, they will be about 110 ,umens per watt. Your QI lamp won't be close to that. However, I really doubt what you have ordered is actually 50 watts so might still be okay. Heat sink applies. If its 50 watts, ypu will probably need at least a 100mm square finned heat sink. I haven't bothered do the calculations.

[MichaelG.]

Heat sink applies. If its 50 watts, ypu will probably need at least a 100mm square finned heat sink.

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Yes, I was expecting to need that; especially as I am hoping to get away with passive cooling.

… as originally stated: I will report back in due course.

MichaelG.

[Saul]

Thanks for your comments, Glot … but they are largely superfluous my situation.

I am hoping to use LED to replace a powerful tungsten-halogen fibre-optic illuminator.
These particular items may, or may not, turn-out to be suitable
… but they are very reasonably priced, and ‘interesting’

MichaelG.

Hi Michael,
Not sure, did you read this:
http://www.photomacrography.net/forum/v ... 25&t=31950
Bottom line - LED light source should be as small as possible and close as possible (please remember heat also !!!) to the fiberoptics light entrance).
COB's are not good choice.

[MichaelG.]

Thanks for that Saul … but I have a plan

MichaelG.

[microb]

Thanks for that Saul … but I have a plan

MichaelG.

Beam reducer, run it through a metre of fiber to mix, and then shoot the results into a lens to create a collimated light source.

Or do something else I guess....