LED illuminator replacement report

[PeteM]

Forum member, Saul, offers a wide variety of LED illuminators. They offer brighter illumination for old scopes and are also an affordable fix for a failed power supply.

Multiple microscope models are supported in two basic styles. One includes provision for both LED and flash. The other is available in 20-watt LED (and even brighter) versions: https://www.ebay.com/itm/265362785969?

I recently bought one of each -- and consider them an option others (including our local Micronauts) might want to consider. Hence, this posting. Saul also provides various darkfield and other stops that cleverly fit into the proper position for various microscope condensers.

The standard version was tested on a Reichert Microstar IV. This is a new mounting design. It works well with all but a 4x objective, where the fly eye lens in front of the LED -- in combination with the older American Optical DIC condenser on this - didn't evenly or entirely cover the field. The image is now bright enough that the DIC components no longer need to be on a 100-watt tungsten halogen system. All in all, it's now a pretty spectacular system at 10-20-40-100x and quite usable at 4x. The 20-watt LED should also work well for high magnification phase contrast and darkfield illumination, though I haven't tested those yet.

Saul also offers an add-on fan for the brightest LEDs. It has variable speed, is quiet, and does a decent job of lowering the heat sink and LED temperature.

The LED/flash version was tested on an Olympus BX50, also with DIC. It is also an excellent performer in LED mode. I haven't tried the flash option yet, but it looks like it will take a wide variety of flash heads and provide reasonably even illumination.

Saul's LED implementations use a readily available 3-36 volt 60-watt power supply, with both a potentiometer and a digital voltage display. This has three advantages. First, it works well. Second, should the power supply ever fail, a replacement should be easy to find. Third, it's possible to remove the lid of the power supply and tuck the whole thing into many microscopes. Both the digital voltage display and/or the potentiometer could be relocated with a soldering pencil, some wire, and heat shrink tubing in hand.

I've tucked a replacement power supply inside the Reichert MicroStar IV with the potentiometer and display conveniently placed. There's plenty of room to fit it into something like a BX40 or 50 and likely recent Leitz, Olympus BH2, and Nikon Labophot/Optiphot models.

The supply works fine externally, of course, for smaller scopes. Many older scopes have superb mechanical quality and first-rate objectives available - suffering only from somewhat dated illumination. I'd think many users might find a $200-500 scope, add a $165 illuminator, and have a more capable and expandable scope than something two or three times the price new.
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[PeteM]

Some pix added.

[houstontx]

Thanks for the tip, I notice retrodiode has closed up shop...I have a BX60 with DIC, need brightest LED and want flash too, good to know, thanks!

[Scoper]

Do you have a picture of the 4x light coverage?

Thanks

[PeteM]

Do you have a picture of the 4x light coverage? . . .Thanks

No - and I've put the scope away. The illuminated field is a circle inscribed a tiny bit inside the eyepiece view. That limitation is likely the field aperture as seen through the condenser. Quite usable for scanning. The illumination has a hot spot in the middle. Fine for scanning. Probably not so good for photography. All other magnifications looked pleasing to the eye.

A camera might be more discerning. For this scope, it was a big improvement over 20w halogen and DIC.

For the Olympus BX50, it looked good - again to the eye - at all magnifications. That version has a larger fly eye lens.