Suggestions for a DIY PZO Biolar lamphouse/illuminator

Smokedaddy · Post by **Smokedaddy** » Tue Apr 03, 2018 10:09 pm

Thanks ... so what's involved removing and replacing it? Also, does it create a huge hot spot on the image being photographed and stacked?

-JW:

GaryB · Post by **GaryB** » Tue Apr 03, 2018 10:24 pm

Thanks ... so what's involved removing and replacing it? Also, does it create a huge hot spot on the image being photographed and stacked?

No hot spots if done correctly. The general process is to place the emitter at the same position the original halogen bulb filament would go. The LED emitter is about the same size as a halogen coil which means that in the same position as the original filament, the light would essentially be identical to it's halogen counterpart except for color temp and brightness. The advantages are cooler running and very long life. The LED is only about $7 or so, any 12v wallwart will run it and if you use something like a 1 amp buck-puck constant current driver with wired dimmer ($16) you'll have all you need to run it, you just need to make a bracket for the LED fitted to a heatsink.

Buck Puck
https://www.ledsupply.com/led-drivers/b ... ed-drivers

There are a number of threads here showing the process of LED upgrades.

Smokedaddy · Post by **Smokedaddy** » Tue Apr 03, 2018 10:29 pm

So can this existing one be removed replaced with the one you're suggesting?

GaryB · Post by **GaryB** » Tue Apr 03, 2018 10:38 pm

In theory, yes. I say that because I don't know if it's attached with heat transfer epoxy or not. The link I gave for the xhp35 may not fit as I think the dies are different sizes, however here's an ebay link that should fit.
https://www.ebay.com/itm/Cree-XH35-12V- ... B8EL9MrMjg

I think your die is 16mm diameter, so select that size. You have machining tools as I recall, so if the old chip is glued in, you may have to ream it out before fitting the new chip. If it's thermal tape just pry it out. Fit the XHP in it's place and you're off to the races with bazillions of lumens. If that's still not enough, the XHP 50 is waiting in the wings with over 2500 lumens

Oh, if you do end up with the XHP50, you'll need a bigger heat sink! It's a 19 watt chip and it can run pretty hot, or add a small computer fan.

GaryB · Post by **GaryB** » Tue Apr 03, 2018 11:13 pm

Another link for the high intensity (no dome) version
http://www.kaidomain.com/p/S026095.Cree ... pper-MCPCB

I know nothing of these last two sellers personally. The chips I buy are generally 22mm stars.

Pau · Post by **Pau** » Wed Apr 04, 2018 12:48 am

GaryB wrote:I use Cree XHP 35, 50 and 70 with upto 4,000 lumens! They are extremely bright and used in streetlights and car headlights. They make great hi-power halogen replacements.

Not sure about the 35 (it seems adequate) but XHP 50 and 70 are made of 4 chips and the diameter is wider, so I think that despite more powerful than the XM-L2 they are less adequate as substitute of the lamp filament in a Köhler illumination design of classic microscopes

About color temperature, I would recommend neutral white 5000K to 4000K, in my limited experience they provide better spectrum than both warm and blueish ones and white balance is easier to get right.

GaryB · Post by **GaryB** » Wed Apr 04, 2018 1:05 am

The 35 is the same size as the XM-L, just very bright. The other two are 4 chip, that's why I suggested that over the others. They'll work, but as you say, less than ideal sizes. However, if maximum lumens is required, they will do for darkfield but way too strong for brightfield. Even the 50 is monstrous for most purposes but if I ever manage to get an epi head, that's where it's going.

The numbers are actually the size of the emitters.

35=3.5mm
50=5mm
70=7mm

I thought they meant something else at first, the things you learn

JohnyM · Post by **JohnyM** » Wed Apr 04, 2018 1:25 am

100w halogen is giving <strike>3500</strike> 1500-1800 lumens spreaded all around the bulb. How much can you collect? As much as fits into collector aperture and auxilary mirror.

Proper led (be sure to pick one with single chip, not one with 4+) can punch similar number at angle below 120 degree - so you can collect almost everything. Do a reasearch for a led with single chip, smallest angle and highest output. Look out for color temperature and CRI index:
http://technologyfront.com/journalism/a ... 588054.gif
You might want to avoid "cold" low CRI ones, with dominant spike at 450nm.

I use my mods with success for DIC or to excite fluorescence for years. Well, must be a reason why all big manufacturers offer LED options for their scopes, even to excite fluorescence. Be careful of advices from theoricists that never saw Biolar microscope.
Whole "modification" is to put LED exactly where your tungsten bulb filament was. Illuminator on your photos looks good, and should work good if it provides proper positioning. Basically, led needs to be very close to the collector lens.

Smokedaddy · Post by **Smokedaddy** » Wed Apr 04, 2018 10:11 am

Lots of information to digest here, at least for me. Who would of thought that something so simple be so complex. I wonder how they got by with a simple mirror and sunlight or a candle back in the day. <g>

In the past I've purchased LED bulbs for my toy hauler or installed LED bulbs for taillights. Not much research involved, just plug and play. The LED bulb I'm holding is about 15mm in diameter. I assume that pretty typical bulb that I could buy somewhere and then change out the LED? Is that correct? Since this seems to be so complicated (to me) I would like to gather ALL of the information I need LED wise so it will preform properly 'and' information about the aluminum LED holder before I head over to a LED flashlight forum.

-JW:

GaryB · Post by **GaryB** » Wed Apr 04, 2018 10:40 am

It should be 16mm, one of the two standard Cree sizes. The XHP30 16mm die linked previously on ebay will be a direct swap out for your existing chip. Add a 12v supply and appropriate driver/dimmer like the Buck Puck.

Really, that's all it is. It'll look the same as it does now and hopefully be as bright as you need.

Smokedaddy · Post by **Smokedaddy** » Wed Apr 04, 2018 11:17 am

GaryB wrote:It should be 16mm ...

... thanks, I was referring to the 'plug'. <g> Yes the LED chip holder is 16mm.

Pau · Post by **Pau** » Wed Apr 04, 2018 11:28 am

I sympathize with your trouble, I was in the very same situation about two (three?) years ago.

What I have (all easy to find):

Cree XM-L2 neutral white 5000K mounted in 20mm board (don't buy it unmounted as soldering it is very delicate)
You can change the diameter of the board or the LED for the XHP35

Thermal adhesive paste to fix it to the aluminum rod or heat sink without needing screws

The aluminum rod designed and made by Glen (75RR) to mount in the Lamphouse 60 (you need a different rod to fit your PZO)

BuckBlock A009 constant current driver 2100mA
http://www.luxdrive.com/products/buckbl ... ed-driver/

- Logarithmic pot 20K Ohm
https://www.ebay.com/itm/20K-OHM-Logari ... XQMMNR58J2
it controls intensity a bit better than linear ones but the lowest working set is already very intense.

Generic DC 12V power source
In plus I have a cable with connectors a power switch and a small red LED connected with a resistance all mounted in a box

Smokedaddy · Post by **Smokedaddy** » Wed Apr 04, 2018 12:52 pm

Thanks Pau, GaryB etc.,

... learning all the nomenclature. I did watch a informative video on re-flow solder on a LED emitter. Still looking for one that actually shows the process of removing and replacing a 'mounted' Cree.

https://www.youtube.com/watch?v=B3F68ubfBkk

-JW:

Smokedaddy · Post by **Smokedaddy** » Wed Apr 04, 2018 3:09 pm

So when I switch out the LED to something with more output light can I still use this? Just a few cell phone pics.

-JW: