Quick cheap & easy LED conversion for my Halogen 'scope

[mrsonchus]

Hi all, I've just received (on a slow-boat-from-China) the controller for a conversion of my SP200's 6V 20W Halogen light to LED....
Haven't time to do the job yet, but here are some pictures of the parts working well....

The bits & pieces, a 12V (actually it's variable in discreet steps) power-supply, the 12V-in LED dimmer and a 12V multi-LED 'light-bulb' to be controlled with the dimmer....

ws_LED-dimmer-kit.jpg (100.11 KiB) Viewed 20392 times

power into dimmer,

ws_LED-power-supply.jpg (76.35 KiB) Viewed 20392 times

dimmer-control with LED plugged straight into it for testing, obviously it will be in place of the current Halogen bulb when fitted..

ws_LED-controller.jpg (57.8 KiB) Viewed 20392 times

Here's the LED light on,

ws_LED-working.jpg (43.69 KiB) Viewed 20392 times

Here's a short video of it working, with my multi-meter showing the voltage across the LED-'bulb', being controlled by the dimmer..


The dimmer was £1.96 delivered! The bulb/s were £1.99 for 3 - I put one into my 12V stereo 'scope's base and it simply worked immediately, dimming perfectly!

The power-supply I had in a drawer. Total cost to me was therefore about £3...


I may even add the ability to switch to battery-pack.

[Dale]

Have had this on my back-burner for ages. I have the same controller on a wish list, but could not find a source
for a disc of diodes like you have there. Question-why not run the led's straight from the little power supply? Did
you want a finer control?
Dale.

[75RR]

Hi mrsonchus,

could you show us the inside of the dimmer box and the underneath of the LED combo? Thanks

[mrsonchus]

Have had this on my back-burner for ages. I have the same controller on a wish list, but could not find a source
for a disc of diodes like you have there. Question-why not run the led's straight from the little power supply? Did
you want a finer control?
Dale.

Indeed I did Dale, the finer control and ability to alter smoothly the brightness of the 'bulb' - a dimmer that is.
It works beautifully and will also enable me to 'convert' my 'scope in a reversible fashion.

[mrsonchus]

Hi mrsonchus,

could you show us the inside of the dimmer box and the underneath of the LED combo? Thanks

Certainly can 75' - I'll post the relevant pictures later today.

[mrsonchus]

I chose this type of 'pseudo-bulb' arrangement simply because it is able to go straight into a common 'G4' bulb-holder (a new ceramic one is only £1.02!) that requires the two 'prongs' from the bulb - on my stereo 'scope one of these simply plugged straight into the socket formerly occupied by it's originally halogen bulb - a direct replacement that worked (dimmer-function also) immediately.
I've been using that setup every day for a couple of months now and the 'smd' LED pseudo-bulb has performed faultlessly. Also of course any location formerly housing the extremely hot halogen bulb will easily handle this device thermally speaking.

Nice to have a light source that is (significantly) brighter - even in the simple 'hold it over my field diaphragm' test I made, the LED gave me a clearer image and a light that when turned up or down didn't change colour and therefore the white-balance of the camera's image (not to mention that of my eyes)..

I could go the whole way and fully integrate this with my 'scope and may well do so after say a month of satisfactory use - but plan in the first instance to simply usurp the halogen with the LEDs and place the controller either next to my 'scope of perhaps simply double-tape it to the side of my 'scope - simple is always best in the v1.1 incarnation I think.

I'll post the finished article when I make the change - it'll be a few days yet though, lots on at the moment.

[billbillt]

Hi John,

I also am a big fan of LED lighting for Microscopy... I have built several different versions to suit different requirements... Yours is a very good set up... I feel that one day LED's will replace incandescent lighting completely... May I ask what was the wattage of this device?... A person looking to buy materials for this type of project can almost completely buy everything from Ebay for very little money...

BillT

[billben74]

I'm yet another person with an LED upgrade.
So watching with keen interest.

I only have a 20 W halogen powering my main scope.
Would like more beef with say a 10W LED or somesuch.
One issue is that Helen from Brunel had mentioned that LEDs can cause darkfield condensers to gain a blue glow to the darkfield.

Anyone heard of this issue or know somthing about it?

[mrsonchus]

Hi Bill, never heard of this phenomenon but I'd take Helen's word for it - I've never known her to be wrong. But, I'm certain this is not an unheard of effect and there will without doubt be a simple way either to avoid this with particular types of LED perhaps, or maybe more simply with a filter - how about the 'daylight' filter ubiquitous on the front of cameras, they are or at least were supposed to remove a certain 'blue-ness' but whether this was because of the old 'wet' film + paper technology or optics I don't know. I'd take it as read that there's either a workaround or elimination technique if it's significant, which I rather doubt....

I've some more pictures of this in use atop my field-diaphragm without Kohler of course - I'm going to fit this within the next week or so I expect - I like the white light for starters!

[billben74]

I agree about Helen.
But I'm also thinking there must be workaround.

My initial thought had been bulbs with different colours/illumination spectrum.
Maybe a "warm" white coloured LED?
But I can see that a filter is basically a similar idea.
Any one of the more technically able forum members any educated guesses/knowledge of what might be going on?

[billbillt]

This may be from the concern that some people have for the supposedly high amounts of UV generated with LED's... I feel that a UV camera filter in the way would stop this?.... The "warm white" LED's I think are a color preference.. I prefer it over the "cool white" .. The "warm white" seems more like natural sunlight to me.. The "cool light" resembles the sterile lighting in a doctors office... It mimics fluorescent lighting to me ... just MHO...

BillT

[billben74]

I'm guessing you have a darkfield condenser, mrsonchus?
Are you planning to convert your main scope or just your stereo?
Would this represent a possible test?

[mrsonchus]

Hi Billben

No I haven't got a dark-field condenser - just a rather tragic abbe 1.25 at the moment. I've already converted my stereo 'scope with the same bulb (I bought a packet of 3 for about £2.50) although that 'conversion consisted simply of replacing the G4 Halogen in the stereo (12V) with the LED also 12V 'bulb' - it worked perfectly, doesn't cook specimens and has been in use every day for about 3 months now.
This conversion is of my 6V-halogen 20W 'big scope' and has required the addition of a 12V ps, the dimmer-control that is rated at 12V-24V 8A and of course the dimmable 12V LED smd - as used in my stereo 'scope.

[mrsonchus]

Had a go at using this tonight, stuck with an elastic-band and 'blue-tack' straight onto the top of my 'scope's field-iris and lens assembly - no Kohler of course but a good practice for the conversion; here are some pictures as requested, of the back of the LED smd and the 'innards' (pcb) of the controller itself, the whole thing works perfectly - I used it tonight for an hour solid without any hint of a problem...

The back of the LED 'bulb',

ws_LED-controller-(1).jpg (63.29 KiB) Viewed 20342 times

The 'innards' of the controller,

ws_LED-controller-(7).jpg (88.18 KiB) Viewed 20342 times

Prototype v2.0,

ws_LED controller (11).jpg (42.79 KiB) Viewed 20342 times

A couple of quick pictures from the rig, no Kohler and a bit 'Heath-Robinson' but demonstrates the principle I think...

ws_LED images (2).jpg (72.47 KiB) Viewed 20342 times

and

ws_LED images (1).jpg (72.25 KiB) Viewed 20342 times

It'll be good to get this fitted when I get a bit of spare time.

I've measurements taken with a multimeter of the voltage, current and calculated wattage at 25%, 50%, 75% and 100% of the controllers range of travel, I'll post these tomorrow asap.. Roughly it runs at 100% at about 14V and 3W, with about 200mA current as I remember..
It's very bright at 100% and doesn't get anywhere near as hot as the mini-star that is the halogen bulb!

[yoicks]

Re: UV created by LED light source. This is probably beyond whatever level of expertise I possess, if any, but I have understood that one needs specialized optics, such as quartz objective and condenser lenses to pass UV light for fluorescence microscopy, and that ordinary glass lenses block UV.

[billbillt]

Hi Yoicks,

A while back there was a growing worry on some of the forums about UV emissions from LED's... The scare was that LED's would damage a person's eyesight if used for a length of time for microscopy... I have read pro's and con's about this.... I still use LED lighting whenever needed, as I have some stands that have no built in light source...

The Best,
BillT

[billporter1456]

I'm yet another person with an LED upgrade.
So watching with keen interest.

I only have a 20 W halogen powering my main scope.
Would like more beef with say a 10W LED or somesuch.
One issue is that Helen from Brunel had mentioned that LEDs can cause darkfield condensers to gain a blue glow to the darkfield.

Anyone heard of this issue or know somthing about it?

I have noticed that protists take on a blue color when using my homemade LED illumination setup. Here's a couple of videos showing it:



And here's one showing a shift to a pink color:

[zzffnn]

If you know the exact part number of your LED, look it up from the manufacturer. Cree, for example, offers spectrum output graph for their LEDs. LEDs having high UV output are actually specially made for that purpose and are not cheap.

[billben74]

Thanks for the information billporter and zzffnn

[mrsonchus]

Hi all, finished the conversion of my 'scope this evening - it's working superbly and is literally a very cool conversion!

The operating-table...

ws_DSCN3509.jpg (70.78 KiB) Viewed 20272 times

Into existing 'G4' bulb-holder in place of the halogen, disconnected (and of course safely 'capped-off') existing 6V power to bulb-holder then connected back of bulb-holder to LED dimmer and ran out of the rear of my 'scope's base...

ws_DSCN3510.jpg (56.31 KiB) Viewed 20272 times

Mounted LED controller onto side of 'scope with double-sided sponge-tape in a very convenient position,

ws_DSCN3516.jpg (69.63 KiB) Viewed 20272 times

Power into (large plug-in jack) and out of (thinner wires to bulb-holder) LED controller,

ws_DSCN3518.jpg (35.22 KiB) Viewed 20272 times

Working beautifully, tried it for 90 mins use tonight - works perfectly, runs completely cool and gives me images through camera that now match exactly what I see through the 'scope - no more white-balance shenanigans. The rather budget 2mp Toupcam that sits in my 'scope's trinoc tube is now giving me far superior images than it ever did with the halogen system..

Here's a nice 6-image stack with focus running down the perforated cell-wall of a Daffodil-ovary tissue, no WB adjustments applied!

ws_LED--tel03-first-pic-ves.jpg (228.3 KiB) Viewed 20270 times

I'm very pleased indeed with this simple quick and easy conversion - I may connect the 'scope's on/off swith and if suitable) rheostat also when I get the chance, and internalize the the teeny PCB that is inside the dimmer's enclosure.

It's about the same brightness as the halogen it replaces and runs at about 3W as measure (calculated) by myself with a multi-meter, but the controller's rated at 8A and 12-24V so I should be able to simply put a higher wattage bulb in anytime and I'll order a couple and give them a try - this system amazingly leaves my 'scope's body completely cool in operation, the halogen makes it really very warm to the touch, let alone the effect it may have had upon my slides, especially before they had mautured and fully 'set'...

Total cost was about £5 (GBP).

[75RR]

Thanks for showing the "internals" and the back of the LED + final setup.
Glad it is working for you. Can't really argue with £5

[billbillt]

That worked out to perfection, John!... I am glad you did it.... This should be an inspiration for anyone thinking about conversion to LED...

BillT

[mrsonchus]

Thanks Bill & 75' - it was so much easier to do than I at first thought it would be - and for £5! I suppose to be fair I should also include another £8 in the cost as I bought a new 12v 'LED' power supply - in name only I suspect! I didn't need this really as the switchable-voltage supply I used for the prototype would have done the trick, but the new one is very nice, no hint of interference of any kind, and it runs very cool indeed - barely gets warm at all in fact. So, the cost may be better estimated to be between £5 and £13 for the sake of completion.
I must say my 'scope, especially the camera-image side of things, is now performing even better than before the conversion, I really am very pleased with this piece of kit!

p.s. if you're wondering about those tiny fittings they are from the world of CCTV-camera fittings I believe, and cost under £1 for 2, delivered!

[mrsonchus]

Hi again, here's a very short video of the LED-bulb in-situ and working...


Lovely job!

p.s. here's another of these bulbs put directly into the place of the 12V halogen-bulb that my stereo 'scope came with - no work needed here, it worked perfectly, dimmer included, straight away and has been doing so for the past few months now - my SP200 of course had 6V power and needed 'conversion', both 'scopes are now LED - Hussar!

ws_DSCN3508.jpg (27.04 KiB) Viewed 20261 times

[billbillt]

I bought some of the camera fittings also:

http://www.ebay.com/itm/111758608736?_t ... EBIDX%3AIT

cheap..

BillT

[mrsonchus]

I bought some of the camera fittings also:

http://www.ebay.com/itm/111758608736?_t ... EBIDX%3AIT

cheap..

BillT

They're the ones Bill, perfect for the job, I've ordered some more to give me a nice plug-in connection for the 12V 'mini-hotplate' I made some time ago now, I use it constantly (in fact it's in some of my histology pictures) and these are again perfect for the job.

I've a few 12V 5W (dimmable) LEDs on order also, they're so cheap I thought they would sit nicely in my newly-converted 'scope. Note the 'no UV' in their spec' also.

5W LED.JPG (69.06 KiB) Viewed 20216 times

See them here, http://www.amazon.co.uk/gp/product/B014 ... TE_3p_dp_1

The conversion is working perfectly - I've added a small in-line on/off switch also and now have a lovely cool LED light-source!

[einman]

Hi all, finished the conversion of my 'scope this evening - it's working superbly and is literally a very cool conversion!

The operating-table...

ws_DSCN3509.jpg

Into existing 'G4' bulb-holder in place of the halogen, disconnected (and of course safely 'capped-off') existing 6V power to bulb-holder then connected back of bulb-holder to LED dimmer and ran out of the rear of my 'scope's base...

ws_DSCN3510.jpg

Mounted LED controller onto side of 'scope with double-sided sponge-tape in a very convenient position,

ws_DSCN3516.jpg

Power into (large plug-in jack) and out of (thinner wires to bulb-holder) LED controller,

ws_DSCN3518.jpg

Working beautifully, tried it for 90 mins use tonight - works perfectly, runs completely cool and gives me images through camera that now match exactly what I see through the 'scope - no more white-balance shenanigans. The rather budget 2mp Toupcam that sits in my 'scope's trinoc tube is now giving me far superior images than it ever did with the halogen system..

Here's a nice 6-image stack with focus running down the perforated cell-wall of a Daffodil-ovary tissue, no WB adjustments applied!

ws_LED--tel03-first-pic-ves.jpg

I'm very pleased indeed with this simple quick and easy conversion - I may connect the 'scope's on/off swith and if suitable) rheostat also when I get the chance, and internalize the the teeny PCB that is inside the dimmer's enclosure.

It's about the same brightness as the halogen it replaces and runs at about 3W as measure (calculated) by myself with a multi-meter, but the controller's rated at 8A and 12-24V so I should be able to simply put a higher wattage bulb in anytime and I'll order a couple and give them a try - this system amazingly leaves my 'scope's body completely cool in operation, the halogen makes it really very warm to the touch, let alone the effect it may have had upon my slides, especially before they had mautured and fully 'set'...

Total cost was about £5 (GBP).

What does the same slide look like with the original illumination?

[einman]

This is beyond me. And I was proud of the fact I converted an LED illuminated stereoscope from A/C to battery power!!

[mrsonchus]

This is beyond me. And I was proud of the fact I converted an LED illuminated stereoscope from A/C to battery power!!

Hi einman, yes a battery-pack is very handy. My setup ('scope) is now able to take any power-supply from 12V to 24V (as handled by the LED-dimmer control) with matching spec' bulb of course. As in pictures above, the power into the controller I've connected with simple 'jacks' as found on tablet-chargers, 'phone chargers etc. This enables either a battery-pack or a DC/mains power supply as preferred - really handy to have both the voltage range and the ability to use any power-source as long as it has the (2.1mm) jack fitted to plug into the dimmer-control. I also put this together deliberately to have the flexibility to enable the easy return to it's original state of 6V halogen and mains adapter for any future re-sale or part-exchange etc that I may make.

It works very well indeed, and so cheap!

p.s. I'll see if I can find a (halogen-bulb) picture of this slide in my collection, if I find one I'll put them up together for an idea of how they compare, although the halogen especially always needed pp as my camera really 'didn't get on with it'..

[billbillt]

Hi John,

My last post seems to have disappeared.. I am anxiously waiting to see how the 5W G4 bulbs work out.. I once did a comparison test with a 2W G4 bulb vs a 50W halogen... The 2w lost out on brightness.. I was thinking... Half of the G4's COB LED's are on the back side... Maybe a small mirror placed there could help reflect the light towards the front.. Does your dimmer completely turn off the bulb? I have some of the same dimmers here and they do not completely extinguish the light.. I think these controllers are PWM devices... The beauty of all this is it is so inexpensive a person can experiment to no end...

The Best,
BillT