Do you think that would work for a led conversion?

[smollerthings]

Hi all,
I am thinking to led convert the light below:


Would

This
https://www.aliexpress.com/item/1005003018696715.html

paired with this
https://www.aliexpress.com/item/32957373509.html

and with a generic 12v transformer work?

Should I take the led with 30 degrees light cone or 120 degrees?

Thanks

[Hobbyst46]

Looks like it will work, but:
1. 1W is not bright enough for a typical microscope. I would start with 3W and preferably higher, but a heat sink is a must.
2. The LEDs dies themselves are tiny, likely a diffuser will be required to provide even illumination, and a diffuser can cut the brightness considerably -
another reason to start with a higher luminosity lamp.
3. Since the provided light beam is 15mm diamater at most, I think a 120 degrees would be better than 30 degrees.
4. Not a transformer, but a 12VDC power supply, of current rating according to the chosen lamp.

[smollerthings]

Thanks for the answers, I am limited by the diameter so I will actually go to 2w. Do you know if those dimmers are pwm or just a potentiometer?

[viktor j nilsson]

I think that you would be much happier if you acquired an aluminum rod of the same diameter to use as a heat sink, and use a 5w or 10w high quality power led.

[MicroBob]

I would prefer for general use a 10W LED on star or round board, screwed onto an aluminium rod or copper end cap on a piece of installation copper tube. Power source cheap lab power supply with adjustable current. Very versatile and powerfull.

[smollerthings]

I think that you would be much happier if you acquired an aluminum rod of the same diameter to use as a heat sink, and use a 5w or 10w high quality power led.

I dread cutting that thick piece of metal though...

[viktor j nilsson]

I think that you would be much happier if you acquired an aluminum rod of the same diameter to use as a heat sink, and use a 5w or 10w high quality power led.

I dread cutting that thick piece of metal though...

What diameter is the thinner part of the sleeve? Can't be much more than 25mm? Aluminum of that diameter isn't hard to cut with a hacksaw.

[MicroBob]

I meant these caps: https://www.wholesaleindustrialsupply.c ... e-end-cap/

[PeteM]

I meant these caps: https://www.wholesaleindustrialsupply.c ... e-end-cap/

Clever idea. Easy enough to add a bit more copper tube inside as well - maybe useful for attachment as well as a larger mass. It might be worthwhile to flatten (sand) the end a bit, before putting thermal paste between the LED die and the copper end cap. The stamped ones around here are often a bit domed.

[smollerthings]

I meant these caps: https://www.wholesaleindustrialsupply.c ... e-end-cap/

Mmm I like this idea. With 2 caps and a tube, one can achieve easily any configuration.

[BramHuntingNematodes]

I think I said this before but on devices like this I have broken the glass out of the bulb (dont cut yourself!) and soldered leads and a starboard on to the lamp leads so as to maintain correct filament placement. Small aluminum heatsinks can be easily be cut to size and cemented to the boards (you can insulate your leads with llquid electrical tape if youre worried about shorts) I use 10w leds for these setups and it works very well with a minimum of alterations to the equipment.

[smollerthings]

I think I said this before but on devices like this I have broken the glass out of the bulb (dont cut yourself!) and soldered leads and a starboard on to the lamp leads so as to maintain correct filament placement. Small aluminum heatsinks can be easily be cut to size and cemented to the boards (you can insulate your leads with llquid electrical tape if youre worried about shorts) I use 10w leds for these setups and it works very well with a minimum of alterations to the equipment.

That is an interesting idea. Do you have pics of your conversion? How do you fix the starboard onto the heatsink? Screws? How do you keep the starboard-heatsink unit in place?

[Leitzcycler]

Don't forget to see also my pictures here
viewtopic.php?f=24&t=11044&p=110831&hilit

[smollerthings]

Don't forget to see also my pictures here
viewtopic.php?f=24&t=11044&p=110831&hilit

Awesome. So you rectified the 12v ac to dc and soldered the output directly onto the starboard? And you could dim without flashing?

[Leitzcycler]

It works perfectly for eye. You can see sometimes a minor interference in camera, however you can eliminate this by the camera program.

My intention was restoration of the original transformer for led option simply because I like the style of the transformer and think it is really very cool.

[Leitzcycler]

Have to add that the small led doesn't work well for low power objectives in my system. However, I don't care because as you know, I mostly use 40x and 100x objectives for yeast and bacteria work ... The problem may be also in my condenser (in this model you should unscrew the top lens to get low aperture, and I haven't even tried that; haven't had time as I am struggling with totally different kind of problems in the lab)

[smollerthings]

It works perfectly for eye. You can see sometimes a minor interference in camera, however you can eliminate this by the camera program.

Playing with shutter speed?

My intention was restoration of the original transformer for led option simply because I like the style of the transformer and think it is really very cool.

It looks indeed very cool

[Leitzcycler]

Playing with shutter speed?

There is anti-flicker function in the program, which I don't understand more deeply. However, my big condenser eliminates it mostly.

[BramHuntingNematodes]

Her is a 7-watt narrow-spectrum green LED in a Nikon Universal microscope lamp. There is a good filament adjustment system on this lamp, and some specifically placed lenses, so I wanted to match the old mazda as well as I could. I don't have a heatsink on this one looks like, so I might lose some efficiency. I have left this one on overnight and haven't had problems.

[BramHuntingNematodes]

Oh also, you can use your good old 10v DC power supply-- in fact you'll need one. Just install a buck puck inline between the LED and the power supply, optionally a potentiometer to control dimming.

[MichaelG.]

.
Seems reasonable to assume that the LED would need mounting at 90° compared to that one.

… or does the Neopan unit include a mirror ?

MichaelG.

[smollerthings]

However, my big condenser eliminates it mostly.

Ooo? Your condenser eliminates the flickering? That is mysterious.

I don't have a heatsink on this one looks like, so I might lose some efficiency.

Thanks for the pics!
7w is mighty without a heatsink. I tried 3w the other day without one and it became really extremely hot. I think you may lose some life on the led.

optionally a potentiometer to control dimming.

I am a bit unclear on the dimming part. Potentiometer vs pwm. I guess potentiometer is better because it won't induce additional flickering in case one wants to make videos? I am a bit rusty on the sizing of the potentiometer. What did you use for the 10W?

[MicroBob]

I have left this one on overnight and haven't had problems.

Hi Bram,
was it on on measured full 7W power?
I would expect it to burn out quickly. But practice beats theory of cause.

My preferred solution is a tight tolerance turned aluminium heat sink as it makes best contact to the stand and transfers energy well (and softens up gummed up focus drives! ).
The copper end cap solution will in most cases need a few layers of adhesive tape to fit it into the stand, limiting the possibility to transfer heat into the stand. But the copper tube leads heat well and one can add fins and whatver outside the stand - and no lathe needed.

For a 32W LED in an epi illuminator i used active cooling with a small fan. The illuminator is 3D-printed an d heat build up has to be avoided.

Generally LEDs are nice but their efficiency is still low and the produce more heat than they can stand themselves.

Bob

[MicroBob]

This type of power supply works very well, though not forever on full power:
https://www.ebay.de/itm/133896330570?ha ... Swij1hXWIi

[dtsh]

I converted an AO10 to LED, in doing so I found that the exposed surface area for the heatsink was more important than I had originally imagined. Initially, I had it mounted to a chunk of aluminum, thinking that the mass of the aluminum would be sufficient; however, the LED overheated after extended use and started to burn up. I ended up replacing the large aluminum block with a small 22mmx22mm heatsink; mass-wise the heatsink is but a small fraction of the size of the original block, but it's surface area allows it to disperse the heat more effectively.
I also lapped the heatsink and "star" substrate a bit to allow for improved contact.

I don't think I would go with anything less than 3W and more would be better.

[smollerthings]

This type of power supply works very well, though not forever on full power:
https://www.ebay.de/itm/133896330570?ha ... Swij1hXWIi

What about a cheap wall wart 12v 2.5A, that is 30w which should cover nicely the 10W leds?

[Leitzcycler]

Ooo? Your condenser eliminates the flickering? That is mysterious.

Sorry, I was not thinking in English

Wikipedia:
The capacitor was originally known as a condenser or condensator. ... This name and its cognates are still widely used in many languages, but rarely in English, ...

[smollerthings]

Sorry, I was not thinking in English

I was wondering if you mysteriously stumbled upon a light storing condenser that equalizes light output

[smollerthings]

however, the LED overheated after extended use and started to burn up

Man, we didn't have those problems with halogens. Your samples were burning up but the bulb was totally fine.

[dtsh]

What about a cheap wall wart 12v 2.5A, that is 30w which should cover nicely the 10W leds?

I use a wall-wart with mine, but I use an LED driver which converts the volts and amps to ranges appropriate to the LED and adding a driver increases the cost. I believe the driver was the single most expensive part on mine.