haven't seen people claim LEDs give off no heat. seems obvious to anyone that's used them that they give off some heat, but clearly less than incandescents. also far less UV radiation, which is what fades colors.

how can you claim superbrights don't give off less heat than incandescents when you didn't even test any?

The benefit; isn't the blub... it's the current draw which translates to heat savings in the backbox.

http://www.pinballmedic.net/tech-tips/lamps.html
0.25 amps vs 0.02 amps for a #44 vs LED lamp. Very important over the long run.

LEDs are single wavelengths... Incandescents give off all forms of radiation.

it is nice to see real-world numbers regarding LEDs versus incandescents. we could use more of this, although i'm not sure i understand why you disregarded the 500 degrees recorded at the filament. isn't the incandescent filament about as far away from the plastics as the LED is?

I use LEDs to avoid the heat so as to not damage the plastics.

+1

And aren't the leds like, 100 degrees cooler, even when ignoring the 500 degree heat of the incandescent?

I think to be scientific... one needs to measure the temperature of the PLASTICs; not the bulb.
One way is to use thermocouples at points directly above the "bulb" on the top side of the plastics.

Another would be to take the FLIR picture when the machine is off after a suitable stabilizing time frame. IE bake with glass on for 20minutes. Quickly remove the glass and turn off the machine. then measure with FLIR. Do this for the LED and the INC ... and see if there is a fundamental difference between the plastics in both cases. I think you'll find the plastic is much hotter with INC.

My unscientific observations of pop caps is that direct contact with a incandescent results in a melted spot on the cap, direct contact with an led results in no melted spot. I'll stick with the leds.

He doesn't mention whether the incandescent is a 44 or a 47. Big difference between the two in power consumption. I suspect there would be a big difference in temperature too.

I've never had a 47 damage a plastic. I've seen lots of plastics damaged by 44's, but never by a 47.

You gave details on all the LED's you used, but 'all inc's run hot'?

I know you're trying to make a point here, but if you're going to get technical, you shouldn't generalize about incandescents. If one LED was 71 degrees, another was 140 and the 44 was 217, I'd like to know where a 47 fits in and I'm sure others would too.

what about LEDs with plastic domes over them? or is that what you were using? and if so, were you measuring the dome on the LED or the LED itself? the domed (frosted) ones i have in my GI get warm but they certainly never come close to approaching 200 degrees.

well, there's no reason to be hostile or to make assumptions ... i don't know much about SMDs versus other LEDs. i for one would be interested to see data on superbright temps. however, the peak temperature isn't the whole story, it's merely a variable in the equation (as i'll explain below)

you're assuming thermal radiation is solely a function of the temperature of the source, but that's not how it works. the amount of heat transferred from one surface to another (say a bulb to a plastic) is also dependent on the distance and surface area of the heat source (as well as the target surface's ability to radiate heat away). think of a 500 degree oven heating coil, and a 500 degree incandescent pinball bulb. one is going to heat objects up a whole lot more than the other, even though they're the same temperature. obviously that's an extreme example but the point is measuring the peak temperature of the heat source doesn't tell you whether or not it will heat up plastics near it. isn't the surface area of an SMD tiny? wouldn't it therefore generate only a fraction of the total thermal energy of a big ol' incandescent bulb, even if its peak temperature is the same? i can only hypothesize, but if we really want to answer the question of whether LEDs keep plastics cooler than incandescents, we need to measure the temperature of the plastics in question, not the max temp of the source.

it seems like you want to claim modern superbright LEDs are just as harmful to plastics as incandescents, but you haven't really proven that yet, since you don't have any superbrights, and aren't measuring the temps of the plastics themselves. i am definitely interested in the answer to this question, though - i haven't seen proof either way.

surface area of the heat source is also a variable in calculating the amount of thermal radiation from one object to another. in the case of SMDs, the surface area is tiny. compared to an incandescent, they ought to radiate less thermal energy at the same temperature. comparing the temperatures of the sources is like measuring the RPM of two cars to determine which one is faster.

i just think it'd be most useful to measure the temp of the plastics - cut to the chase and measure the end result with different bulb types. isn't the temperature of the plastic what we care about here?

Incandescent bulbs give off infra red heat much more than standard LEDs used in pinball machines. The IR heat is a factor that cannot be measured on the light source itself - it needs to be measured on the plastics adjacent to the light source.

From my simplistic point of view, I can hold a pinball LED in my hand after its been on all day. Especially a domed LED. If I pull an incandescent bulb and hold it after being on a while, I get burned. Conclusion: LEDs are lower temp than bulbs.

But the biggest savings is in reduced current loading on the power driver circuits of the old pinball machine. Anything that can reduce current load will help preserve the aging pcbs, headers, and IDCs.

40 cfm of fan properly placed to draw in air from the base cabinet and exhaust through the head does more to cool the inside of the machine than going to LEDs. On the other hand if your gameroom gets hot and/or your air conditioning can't cut it, then LEDs can really make a difference in heat output when installed in multiple machines.

i still don't recall people saying LEDs produce no heat... i think that's a bit of a straw man.

This discussion seems all squirly.
I don't see any "data" in the OPs post. I see FUD; but no scientific method.

Well - then people don't understand the basics of electricity. Everything generates heat - even current thru a wire.
Regardless; fine - you've proven they do generate heat.
You haven't disproven they do less damage to plastics.

You made some pretty pictures - I'll give you that. I'm sure they added some value.

LEDs..
More colourful
Generate no less heat
Last longer
Brighter

Excellent, I will still use them.

Geez...tough crowd.

I have built several PCs and have often wondered about this. It seems pretty simple. My BW games get really hot. Where do you plug in your fans? Do you have a picture?

Yup! I think it was in interesting post with good intentions.

I applaud your data and testing, it's always nice to see testing done and results.

It seems as though this is all to attempt to prove a very trivial point - zero heat from an LED bulb. Sure there is "some" heat, but it's nothing like incandescent bulbs for all intents and purposes. There are some LEDs (loosely speaking) such as ultras that burn insanely hot, to the point of where I was afraid because of the heat generated to use them (very sparingly) in the places I have.

There are some LEDs that appear to give off no heat, such as the concaves, but all in all, people state "no heat" insinuating for all intents and purposes there is no heat issues with LEDs, which I think most would unanimously agree with, as opposed to the predecessors.

Less pf heat based on multiple LEDs installed ( who puts in just one?) and .25 a draw from LEDs compared to .9 or more from bulb, translates to severely decreased backbox temps. I did a reading on my IJ. Ambient temp of 79 degrees F, humidity at 30%. With Bulbs installed, board area was at 157 degrees. Hot! After running in attract mode for 1/2 hour.

With LEDs, b&b area temp was 110-111.

Back when I had a bunch of WPC games I used to build boxes with fans. I measured the air temp in my TZ away from the bulbs and boards and it was 30-40 degrees lower in the backbox. The key is to draw the air in from the cabinet and out through the backbox to supplement the natural convection. The box must span all of the holes in the backbox or it will draw air in one hole and right out another rather than drawing it through the whole machine. I used to extremely quiet fans with around 20-30 CFM each. Any more is not needed. Before anyone asks, I've had fans in an AFM for over 11 years now and there is no excessive buildup of dust.

pinball fan install 2003 011.jpg

but i just gotta ask. are you an avid LED user?

Good idea. Where did you plug them in to the boards?

No, but back when I was making these there were no LEDs available like there are today. Even still I do not LED WPC machines. MY WH2O and IJ have less than 10 LEDs each in strategic spots that needed them.

Gator clip onto ground and the 12volt test point.

Removing 44 & 555 bulbs with game on = burnt fingers,
Removing 44 & 555 l.e.d bulbs with game on = no burnt fingers

Lower heat.
Lower power consumption.
Lower UV output.

We can argue about aesthetics but thems there are just the facts.

Duck season!

LEDs will always 100.00% of the time produce less heat than a bulb with equal brightness. Not even close in fact; usually by a factor of 5 or more.

Size of temp benefit based on led size. But always a benefit WITH LEDs as opposed to bulbs. Yes, size of led matters, but is a minor issue compared to 44/47/555 heat amperage output.

Temperature is not the only factor in heat output. Surface area and heat conductivity of the material are also important. So what I am saying is the bulb could very easily be twice the temperature of an LED, but throw off 5 times more heat into the machine. You also need to make sure you are comparing a bulb that is putting out the same amount of light as the LED. Most LEDs are much brighter than a 555 or 44.

No, I said ultras, they burn very hot. Supers give off a bit of heat, but I've never felt one that was "hot" as I do with incandescent.

The only apples to apples comparison is to center the temp sensor center on the filament/diode in all cases, seems from the pics you aren't always doing this. Also, I'm confused at the images... the pics list inc.jpg as attachment #2 but pic #2 is rendered with 75.6 degrees, maybe best to put the bulb text into the image as the forum is rendering them out of order from its listing.

the temperature of the bulb is a red herring, since the transfer of thermal radiation from one surface to another is dependent on the surface area of the source in question. a large source radiates more heat than a smaller one even if they are the same temp. ive tried to explain that several times. it's why the only meaningful temp measurement would be of the plastics in question, not the bulbs.

i agree with the general premise that LEDs do give off heat, but i think it's probably significantly less than Incandescents, and reduced heat is probably a valid benefit of LEDs.