Replacement light source help

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Lizzy
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Joined: Sat Mar 11, 2023 11:15 pm

Replacement light source help

#1 Post by Lizzy » Wed Mar 29, 2023 9:05 pm

Hi, I am in need of a light source. The bulb is very expensive and I would still need a transformer for it. I was looking for small light sources and found mini spot lights, for artwork. Some run of three double A batteries, but a few are usb rechargeable and can run off a battery pack. Not that I have a field scope, but I do have a solar recharge battery bank, so it could be a compact portable light system with a solar recharger if I pursue that. Most can be dimmed and some come with the ability to change the colors. you can pick warm or cool light and other various controls. I was wondering if anyone could look at the particular one I am interested in and see if it looks doable at all. I am waiting for my microscope to arrive and was hoping to come up with an alternative light source by the time it arrives. I’m not sure if at three inches tall, it is too tall and I might have to raise up the scope to accommodate it. I am getting a Unitron MPH. I made sure to triple check and not type it wrong. MPH!!
Anyhow, I would appreciate any comments. Maybe the idea has been done before, but I have not see this idea posted. I noticed some of these units are intended for outdoors and even are water resistant. If they work, they would be a great light source to have in a field bag for a lot of hobbies or reasons. I am thinking maybe the light itself might need a little diffuser or something over it, so it’s more even? I don’t really know, that’s why i am asking for help.
I am getting a Unitron MPH. I made sure to type it correctly this time. MPH! Thank you, Lizzy

https://www.amazon.com/BIGMONAT-Wirele ... atf_m&th=1

PeteM
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Re: Replacement light source help

#2 Post by PeteM » Wed Mar 29, 2023 9:23 pm

Hi Lizzy, Some microscopes of that era have a sort of socket that could hold either a mirror or a lamp. If yours of this type (post a close-up picture underneath), you can find LED replacements on Ebay that will plug right in.

I've also used LED headlamps - the type with a single LED die and some ability to focus - as lamp replacements. Look around and you might find one that is an easier and better retrofit than the Amazon link.

apochronaut
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Re: Replacement light source help

#3 Post by apochronaut » Wed Mar 29, 2023 11:11 pm

There are a couple of things about older microscope illuminators that confound people trying to source bulbs. One is that once a bulb gets rare, they seem to have a property of causing extra hair growth on those that possess them. This extra hair is called fleece. I don't know why this happens. It just does.
The second thing is that there is something that exists for many things that also exists for microscope bulbs. Subsitutions. Not exactly like basketball players that flood the court during the last 5 minutes of a losing cause. They are usually lousy. Bulb substitutions, if done carefully , can be just as good as the original, but leds :: they need a lot more care in selecting them because their ray characteristics are different.

I am guessing that your MPH is equipped with that odd Unitron illuminator that was situated right under the condenser with the bulb positioned vertically and therefore a horizontal filament. If this is correct, post back. I think there are many good reasons to use the existing lamp and socket but substitute a different bulb, either a 6 volt with the same wattage ( about $4.00 ) or an led with the same base. Irregardless, you will still need some type of intensity regulator. Your illuminator must have a dimming function ; something resembling a transformer is necessary. Fortunately, 6 v. transformers are really cheap but 12 v. can be expensive.
It's anyone's guess why Unitron chose a 12 v. power supply for such a piddly little 12 watt bulb? Since I am part of anyone, I will guess. They had multiple versions of illuminators and decided to standardize on a voltage because they needed more voltage for some of the other illuminators? Ssved them dough maybe?
Anyway, fortunately there are several really inexpensive 6 v. 12 to 18 watt bulbs with the same BA 9s base. Easy fix whether incandescent or there are also a number of led BA9s bulbs, which will run off of a power supply.

Lizzy
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Re: Replacement light source help

#4 Post by Lizzy » Wed Mar 29, 2023 11:57 pm

Yes, it is as you describe. I don’t have it in my hands yet and am trying to come up with an alternative plan. I don’t know if it needs a bulb or the fifty odd year old socket and wiring is bad. And I would need to invest in a transformer or something to dim it down, if it even works. I found a website that described using pinball machine bulbs as a replacement and went on the describe a simple transformer dimmer switch for a MPH microscope. I could go that route and the bulbs are very reasonable, around 11 dollars for ten bulbs.
I was hoping to find a plug and play option. I see items for sale that are sold as a microscope light source I could try. One had a mirror on one side and a led on the other, looks like a possibility. Thanks for helping, Lizzy
https://www.amazon.com/gp/product/B08V ... VZTA&psc=1

https://www.amazon.com/gp/product/B0BQ ... LVDR&psc=1

Lizzy
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Re: Replacement light source help

#5 Post by Lizzy » Thu Mar 30, 2023 12:18 am

I should mention that while I do not know the condition of the wiring, it is a normal two pin plug, to plug into the wall. I noticed most others for sale had a single round plug that would require a specific transformer to fit the plug. I thought it was good that it was a normal plug and if the wiring is good, it might be require a less expensive transformer. I had something floating around to control a stained glass soldering iron. Maybe that would work. Lizzy

apochronaut
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Re: Replacement light source help

#6 Post by apochronaut » Thu Mar 30, 2023 1:05 am

If it is a standard two prong plug for a 110 v. wall receptacle , then it is a basic unregulated mains supply and no transformer is required. I have to admit, I don't know this microscope well but my brother worked for the Canadian distributor in 1967, so I was around them a bit.
Some microscope transformers of the era used sockets that received plugs that if viewed in a photo could look just like a 110 v. wall plug but they were usually a push and twist type with gently curved tines and won't go in a wall socket. The confusing thing is that all kinds of illuminators that just plugged into the wall existed but BA9s based bulbs are not usually 110 v. bulbs, so that vertical socket on the Unitron is likely uses the 8v. bulb with a regulated 12v. max. power supply,
There is no transformer required for a 110v. bulb that plugs into the wall socket and the 110v. bulbs usually are very similar to standard 110v. household bulbs. 110V. illuminators on microscopes were always student grade unregulated illuminators . Cheap to make so they could be just plugged into the lab bench at school and away you go.
The better illuminators were all 6v. with regulators with specialty plugs that couldn't accidentally by jammed into a 110v. line by a dufus. The research stuff were mostly 12v. but they were usually 50 up to 200 watt and regulated too. Those could be had with specialty plugs too or by special order, the same type made for low wattage standard 110v. plugs . That way a new hopeless dufus could electrocute themselves quite quickly,. It was usually cheaper for the lab to pay out the minimal insurance for an intern right away, than for someone even part way into a research career. despite how ridiculous the research was.....Just seeing if you are still awake.
The Unitron MPH data says 8v.12 watt with a 12v. variable power supply (I think). A cheap 6v. power supply with something like a GE 88 6v. 13 watt bulb fitting the same BA 9s socket would do perfectly well. The bulbs are cheap as dirt. Someone on ebay is wearing a fleece coat and wants 56.00. Here is an AVIATION supplier that wants $2.26.They wear leather jackets. Such a difference in material, eh. https://www.univair.com/electrical-ligh ... ight-bulb/ ... go figure.

Chas
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Re: Replacement light source help

#7 Post by Chas » Thu Mar 30, 2023 5:15 pm

Just a word of caution; don't imagine that a 'microscope light source' that you might get from ebay will necessarily fit the microscope that you have. Often they are designed to fit into the hole that the mirror (if it had one) would go into ... the size of these holes varies as does the horizontal distance from this mounting hole to being directly under the condenser.
Last edited by Chas on Thu Mar 30, 2023 6:08 pm, edited 1 time in total.

apochronaut
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Re: Replacement light source help

#8 Post by apochronaut » Thu Mar 30, 2023 5:23 pm

I did a bit of searching on your behalf and there are a myriad of led bulbs now with the ba9s base. I don't think you would need more than one watt. led. Make sure it is a dimmable type. That will take some searching..... or the GE 88 bulb at 13 watts is equivalent to the original bulb, just a different voltage.

You obviously will need an appropriate power supply.

Chas
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Re: Replacement light source help

#9 Post by Chas » Thu Mar 30, 2023 6:07 pm

The MPH's condenser appears to be a bit 'different ' ..it looks to have its ring at the top :
https://www.ebay.com/itm/255456845564
And it seems that rather than changing phase rings, when you change objectives, you rack the condenser up and down.
So maybe that is why the light is mounted to the condenser (?).

Lizzy
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Re: Replacement light source help

#10 Post by Lizzy » Thu Mar 30, 2023 7:38 pm

Yes Chas, that is how it operates. There are markings to show you how to adjust the condenser up and down to match the objective. I think there is a mirror socket still on the frame of mine, but it is hard to tell. If so, I plan on measuring and getting a replacement, just to have on hand. I was going to post that condenser picture since it is the best image out there, but you beat me to it. Here is an image I found of one with a mirror.
1683CEA6-3647-4D66-A5DD-F483C4F3D2F5.jpeg
1683CEA6-3647-4D66-A5DD-F483C4F3D2F5.jpeg (110.83 KiB) Viewed 2443 times
I hope what I got coming works. I thought the system sounded easy to operate for a beginner like me. I suppose that is completely wrong thinking, but oh well. I found some dimmable bulbs on Amazon that I can return. The bright white is 6000k and the warm white is 2700k. Both are .70 watt, which is higher than a lot of them. I read somewhere that older microscope bulbs come in around 3200k, so I guess brighter is better. My eyes are old and tired. If these look good, I can have them by Tuesday. If anyone can look at them, I would sincerely appreciate it. I am very thank for for all the help and comments, especially apochronaut. I am going to have to wait and see what the plug looks like before I can deal with a power supply, if it is specialized. If not, I’m sure there is some sort of electronic thing around here to control power tools to dim it down. Lizzy


#1813, 1816 Miniature Bayonet Bulb LED ... /d/3CP7xWX

apochronaut
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Re: Replacement light source help

#11 Post by apochronaut » Thu Mar 30, 2023 7:59 pm

.7 watt will be pretty bright with the bulb in that location but if dimmable, it should be o.k. Led colour temp. doesn't change when dimmed much if any. There's a 12-24v.. dimmer. Gives you an idea anyway.
https://www.ebay.ca/itm/LED-Dimmer-Swit ... ect=mobile

Phill Brown
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Re: Replacement light source help

#12 Post by Phill Brown » Thu Mar 30, 2023 8:12 pm

I'm going to chip in here with wait and see what you have to work with.
Obsolete microscope bulbs are often just modified bulbs that are still not too hard to find.
Don't bin dead bulbs that have soldered brass colliers that drop off and clean up with some heat.
There are also adapters for one type to another.
BA15D to halogen capsule is a straight plug in, the filament should be very close to the original.
Projector bulbs can be square filament or coiled inline or at a right angle to the bulb.
I'm not sure if my camera sensor likes LED anymore than I do, they can have some colour spikes that are unnatural.
Good luck with the project whichever way it goes.

Chas
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Re: Replacement light source help

#13 Post by Chas » Sat Apr 01, 2023 8:19 pm

As a general purpose light for your microscope this is pretty handy:
Ulanzi March 2023.jpg
Ulanzi March 2023.jpg (79.9 KiB) Viewed 2328 times
Just rest it between the feet, or if the scope is tilted place it on the table in line with axis of the scope.
No wires/power supply needed.

Hobbyst46
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Re: Replacement light source help

#14 Post by Hobbyst46 » Sun Apr 02, 2023 11:10 am

Welcome Lizzy,

I just found an spare old 20X/0.45 phase contrast objective marked "Union". It is probably an achromat and has a parfocality distance of 33 or 36 mm (estimate). In case that Union and Unitron are compatible, I will gladly part with it.

Lizzy
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Re: Replacement light source help

#15 Post by Lizzy » Wed Apr 05, 2023 4:03 am

Sorry for dropping out. I actually had a medical emergency and was in the hospital for several days with a massive kidney stone. My microscope arrived safely yesterday when I was not home, and looks beautiful. I’m hoping the the glass is good, too. The socket for the bulb looks excellent and the plug in is a normal kind that plugs into the wall. When I feel better I will try and experiment with a flashlight or something to see what the glass is like. I’m going to order a bulb and get a simple dimmer switch for the time being. Thanks for the help and when I am feeling better, I will try and get it up and going and post pictures in the My Microscope section. I don’t know if union and Unitron are compatible but will look into it. Thanks to evryone, Lizzy

Chas
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Re: Replacement light source help

#16 Post by Chas » Wed Apr 05, 2023 8:05 pm

Hope you get to feel better soon :-)
Just a note to say ...clean the lenses in your eyepeice first as a foggy eyepiece will ruin the view through all your objectives.
It is very hard to see the lens fogging naturally, so put the eyepiece, upside down, on a mobile phone light, the fog on the big bottom lens will then become apparent.

Lizzy
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Joined: Sat Mar 11, 2023 11:15 pm

Re: Replacement light source help

#17 Post by Lizzy » Wed Apr 05, 2023 9:38 pm

Thank you very much for the tip! I’m basically happy to be alive and home right now. Lizzy

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