Can I use LED bulbs in my Ilford MG 500 head?

[Thodoris Tzalavras]

For the past fifteen years I've been using 120V, 250W ENH Halogen Lamps like this one:

Is it possible to replace them with 120V, 5W LED like this one:

Physical dimensions seem to match.
I'm mostly concerned about safety.

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If you need additional information regarding the specific MG500 setup I have (there were at least a couple) and/or why I'm considering the switch let me know. Hopefully the answer to my question (either positive or negative) is independent of specifics.

[John Brady]

I'm curious myself, I have a Devere 5108 and have wondered if there is an LED bulb that would work in place of the halogens. It seems that the brightness isn't sufficient from what I remember but, when I look at the led bulb you show it's similar.

[interneg]

I think that in something like a 5108 where it's simply a matter of voltage and socket compatibility, as long as the LED outputs enough light, it should be usable. The problem is that there don't seem to be many/ any that can output the equivalent of 250-300w within a suitable ELH/ ENH etc form factor.

The MG500 uses PWM (or something along those lines) with the regular control panel, so you might need to check the compatibility of the LED driver circuit etc.

For what it's worth, Ilford have effectively said that the Heiland LED panel outputs a contrast range very close to the blue/green MG500.

[Eric Woodbury]

For 250W halogen replacement, you will need about 25W of LED for equivalent output power. That's nearly seven CREE 1 amp LEDs. And you will have to keep the LEDs relatively cool and temperature stable: Under 85C at the junction in the LED.

You can certainly try that lamp, but you will have several percent output drift with temperature and overall intensity will be down 5x, almost 2.5 stops. White LEDs will have decay, just as your halogen.

[Thodoris Tzalavras]

Hey guys, thank you for your answers.

Helpful people always try to provide as much relevant information as possible, and I really appreciate that.

My main concern though is that of safety.

So, let me reiterate my question this way:
If I put the LED bulbs (from my link above) in the MG500 head, is there ANY chance that I might damage either the head or the power supply?

Eric's answer is reassuring, but interneg suggests that there might be a compatibility issue…

The bulbs are cheap enough to try them out in terms of proper function, regarding light output, etc…

But I do need some reassurance from someone with a background in electronics that it's ok to do this test.

[ic-racer]

You might want to check out how 120 or 220v LED lamps work before trying to hook one to a pulse-wave-modulated circuit (dimming circuit). Video from the internet, not mine:

[Tin Can]

I would make a separate harness from wall socket to timer to LED

Bypass it all

[Thodoris Tzalavras]

ic-racer,
I was hoping you might chime in.
(you don't know me, but I know you (among many others) through your posts…)

So, thanks for explaining what interneg meant with his mention of PWM.

To be honest, I always thought that the MG500 was adjusting contrast only by the duration each lamp was turned on, but that each lamp was used only at full power, without a dimmer…

By the way, I watched the video you linked to but there was no mention of LEDs having conflicts with dimmers…
The Amazon listing however DOES mention that their lamps should NOT be used with a dimmer…


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Randy,
I already have (and use) a semi-DIY 8x10" horizontal enlarger with an off-the-wall LED light source…

For this enlarger, I'm looking for a possible workaround to a specific problem, and not for a full conversion (at least not if I can avoid it)…


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I didn't post details as to the why I'm considering switching from ENH Halogen to LEDs, thinking that a simple question regarding compatibility and safety would be an easy answer for those how understand electronics…

Maybe I was wrong, so here is some more background info:

I have a (used) Durst L1200 with the MG500 head/power supply and the RH Designs Analyser 500.
It has served me well for over 15 years.

In the particular model I have, the cooling fan runs on a timer.
Every time the focus or the exposure is activated (regardless of duration), the fan runs for 2 minutes.
There are two audible click sounds emanating from the power supply, at the beginning and end of this 2 minute cycle.
A couple weeks ago the cooling fan started acting up.
The click sounds are there, but the fan sometimes works, and sometimes it doesn't.

I did my research (in this and other forums) and armed with the service manual and some user instructions/pictures I opened the head to check for any visible defects (fried cables, or loose connections), but everything looks fine.

I have neither the tools nor (more importantly) the knowhow to conduct an actual investigation as to the cause of the problem.
I also don't have anyone around whom I would trust to do this for me…

So, preparing for when the fan stops working altogether, I thought that if I could use LEDs which don't heat up as much as the Halogens, I could just ignore the whole problem with the fan, and continue using my enlarger as is…

Looks like it might have been wishful thinking on my part…

[Tin Can]

I converted a very old Beseler "Color Head" with bad fan to a computer fan

Way less vibration and higher air flow

Same AC Voltage, less draw

[ic-racer]

Yes, I forgot the Ilford head adjusts time not intensity. I was confusing it with the Philips PCS which alters the intensity of the green and blue lamps.
In that case, I presume the LED lamps will work.