LED Conversion of a BH2 Trinocular

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MicroMan2
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LED Conversion of a BH2 Trinocular

#1 Post by MicroMan2 » Thu May 28, 2020 2:45 am

Does anyone know any LEDs that can replace the 6V 20W Halogen bulb of an Olympus BH2? I would like to know some options that require minimal tinkering with the microscope's electronics. Thank you in advance.

dtsh
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Re: LED Conversion of a BH2 Trinocular

#2 Post by dtsh » Thu May 28, 2020 2:16 pm

I used a Cree XML2 10W when I built a new illuminator for my Brinkmann microscope. The driver I used only pushes it to about 7W, but that seems more than sufficient as I haven't needed to turn it up to the highest setting yet.
(I really should assemble a parts list and diagram and post it someday)

Hobbyst46
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Re: LED Conversion of a BH2 Trinocular

#3 Post by Hobbyst46 » Thu May 28, 2020 4:12 pm

retroDiode.com offer LED illuminators of either a 10W or a 20W cool white LED for the BH2.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MicroMan2
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Re: LED Conversion of a BH2 Trinocular

#4 Post by MicroMan2 » Thu May 28, 2020 5:50 pm

For clarification, you would put these bulbs into the slots, replacing the halogen bulb right? I have some 3.2-3.4 White LEDS with prongs. With those in mind can I use those LEDS and replace it with the bulb?

PeteM
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Re: LED Conversion of a BH2 Trinocular

#5 Post by PeteM » Thu May 28, 2020 6:35 pm

While there are LED assemblies to fit in place of bi-pin halogen bulbs, they're generally not good for microscope use. Typically an array of tiny LED dies and somewhat dim. It would be far worse than the original tungsten-halogen bulb.

You want a very bright LED, with its own power supply and dimmer, arranged so the LED die is about the same size and location of the original bulb's filament.

Another approach is to get a bright fiber optic illuminator and put the end of the fiber bundle at that same location.

Either way there's a bit of work (machining, hacking, 3D printing, etc.) to hold the light source in the right place; typically with a plug-in holder similar to the original BH2 lamp assembly.

Or, buy something like one of the Retrodiode units.

The original lamp on the BH2 is pretty good -- if the power supply works you could just get a bulb . . . That lamp is good for most anything you'd want to view (brightfield, darkfield, polarization, phase contrast) until you get to the very highest powers and want enough light to take photos with reasonably short exposure times.


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ImperatorRex
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Re: LED Conversion of a BH2 Trinocular

#7 Post by ImperatorRex » Thu May 28, 2020 8:28 pm

Another option for a simple LED exchange on Olympus BH2 (orginally 6 V 20 Watt) is decribed here:
https://www.mikroskopie-forum.de/index. ... ic=35833.0

carlh6902
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Re: LED Conversion of a BH2 Trinocular

#8 Post by carlh6902 » Fri May 29, 2020 1:18 am

Just out of curiosity, why are you switching to LED lighting?
--- If you're in the Kansas City area and you need help with an Olympus BH-2 scope, PM me. I love to work on these things ---

MicroMan2
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Re: LED Conversion of a BH2 Trinocular

#9 Post by MicroMan2 » Fri May 29, 2020 1:49 am

Decreased heat emission for longer viewing of water samples as well as preferred color temperature for the light.

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