Railway Preservation News :: View topic - 32V 250W locomotive headlight bulbs, again

jayrod wrote:

LEDs won’t work to throw a beam in a locomotive headlight or even a car headlight with a simple swap. The loco reflector’s parabolic shape is set to focus from a single point light source, the incandescent filament, that is a predetermined distance from the center of the back of the reflector. Those specific bulbs don’t vary in that dimension.

Most LED bulbs in that necessary lumen range are built like a corn cob with many small LEDs arranged around and up & down a column. Or in some other not-useful configuration. All those individual point sources are in the wrong places to focus in the reflector. The best you’ll get is something akin to a flood light.

[edit] Incandescent filaments are for all intents and purposes omni-directional light emitters. Individual LEDs are not. That plays into it also.

In a nutshell, the reflector has to match the design of the light source.

Thank you for the education.

So what I gather from this is, if someone took the time to create a customized "projector" to fit within a typical PN housing and focus the beam properly (something akin to modern automobile LED headlight housing) there might be a way to utilize an LED bulb - but at the cost of losing period aesthetics? Or is that the case?

Another thought that come to mind: How well would LED bulbs hold up in the environment typical with locomotive headlight with regard to heat and vibration?

DC

Author:	Russ Fischer [ Fri May 20, 2022 10:44 am ]
Post subject:	32V 250W locomotive headlight bulbs, again
I know this has been discussed several times in the past but it has become a problem again. AAMSCO Lighting has been a reliable supplier of these for years but has currently ceased production due to supply chain issues. They have no idea when production will resume. Does anyone know of another source of these lamps or a functional alternate. Converting to the standard diesel par lamps is a possibility but we would prefer to maintain the original look and function of the headlights. We go through a fair number of these in our daily operations on the D&S so scouring ebay for the odd one that comes along is not an option. We tried an led lamp that offered a somewhat lower light output but it was unacceptable, partly due to the design not working with the parabolic reflector. Has anyone come up with any new sources or workable ideas since this was last discussed?

Author:	Rick Rowlands [ Sat May 21, 2022 7:35 am ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
I called them a few weeks ago with the same request and was told that they had placed a huge order and it hasn't come in yet. Either way, we are out of luck on those bulbs it appears.

Author:	Donald Cormack [ Thu May 26, 2022 12:34 pm ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
Let me preface by saying electrical engineering is not my background. That said, has there been any successful use of a 2700-3000k LED counterpart? I understand certain marine electrical equipment standardized around the same 32V DC system and there are some LED bulbs that suit that voltage. What are the main barriers to successfully utilizing an LED bulb in place of the 250W incandescent? DC

Author:	jayrod [ Thu May 26, 2022 1:16 pm ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
LEDs won’t work to throw a beam in a locomotive headlight or even a car headlight with a simple swap. The loco reflector’s parabolic shape is set to focus from a single point light source, the incandescent filament, that is a predetermined distance from the center of the back of the reflector. Those specific bulbs don’t vary in that dimension. Most LED bulbs in that necessary lumen range are built like a corn cob with many small LEDs arranged around and up & down a column. Or in some other not-useful configuration. All those individual point sources are in the wrong places to focus in the reflector. The best you’ll get is something akin to a flood light. [edit] Incandescent filaments are for all intents and purposes omni-directional light emitters. Individual LEDs are not. That plays into it also. In a nutshell, the reflector has to match the design of the light source.

Author:	Pegasuspinto [ Thu May 26, 2022 6:08 pm ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
http://railheadcorp.com/product/ke-par56-32v-led/ Yeah it's ugly but it would keep you running until you can get the right bulb. Incidentally it's a PAR56 which is 7 inch headlight. So you can stuff it into a chrome teardrop headlamp housing for maximum tacky factor.

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32V 250W locomotive headlight bulbs, again https://www.rypn.org/forums/viewtopic.php?f=1&t=46582	Page 1 of 1

Author:	Donald Cormack [ Fri May 27, 2022 9:05 am ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
jayrod wrote: LEDs won’t work to throw a beam in a locomotive headlight or even a car headlight with a simple swap. The loco reflector’s parabolic shape is set to focus from a single point light source, the incandescent filament, that is a predetermined distance from the center of the back of the reflector. Those specific bulbs don’t vary in that dimension. Most LED bulbs in that necessary lumen range are built like a corn cob with many small LEDs arranged around and up & down a column. Or in some other not-useful configuration. All those individual point sources are in the wrong places to focus in the reflector. The best you’ll get is something akin to a flood light. [edit] Incandescent filaments are for all intents and purposes omni-directional light emitters. Individual LEDs are not. That plays into it also. In a nutshell, the reflector has to match the design of the light source. Thank you for the education. So what I gather from this is, if someone took the time to create a customized "projector" to fit within a typical PN housing and focus the beam properly (something akin to modern automobile LED headlight housing) there might be a way to utilize an LED bulb - but at the cost of losing period aesthetics? Or is that the case? Another thought that come to mind: How well would LED bulbs hold up in the environment typical with locomotive headlight with regard to heat and vibration? DC

Author:	Jennie K [ Fri May 27, 2022 11:05 am ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
LED lamps have won over the outdoor amusement industry. While in the beginning the high initial cost caused some concerned, compared to the traditional mazda lamps they were used to using, it was a win win situation. It was standard operating procedure having to replace lamps almost weekly, between the set up, take down and actual operation of the rides, the LED lamps however were found to last at least an entire season. As far as the heat, well in most instances they are exposed to direct sunlight a good part of the day, as it's common practice to have the lights on when the ride is open, regardless of the time of day. The other thing that caught their attention is that the LED lamps consume a fraction of the energy that a traditional incandescent lamp uses. There have been instances where the lighting on a ride used more electricity than what it took to operate the ride itself. Considering that for the most part the traveling shows rely upon diesel generators to furnish power, less demand means less fuel used.

Author:	jayrod [ Fri May 27, 2022 8:16 pm ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
Donald Cormack wrote: jayrod wrote: LEDs won’t work to throw a beam in a locomotive headlight or even a car headlight with a simple swap. The loco reflector’s parabolic shape is set to focus from a single point light source, the incandescent filament, that is a predetermined distance from the center of the back of the reflector. Those specific bulbs don’t vary in that dimension. Most LED bulbs in that necessary lumen range are built like a corn cob with many small LEDs arranged around and up & down a column. Or in some other not-useful configuration. All those individual point sources are in the wrong places to focus in the reflector. The best you’ll get is something akin to a flood light. [edit] Incandescent filaments are for all intents and purposes omni-directional light emitters. Individual LEDs are not. That plays into it also. In a nutshell, the reflector has to match the design of the light source. Thank you for the education. So what I gather from this is, if someone took the time to create a customized "projector" to fit within a typical PN housing and focus the beam properly (something akin to modern automobile LED headlight housing) there might be a way to utilize an LED bulb - but at the cost of losing period aesthetics? Or is that the case? Another thought that come to mind: How well would LED bulbs hold up in the environment typical with locomotive headlight with regard to heat and vibration? DC Ooooo, good questions. I have no clue what a specifically designed reflector may look like. My initial guess would be something faceted and, not to mention, hideously expensive for a one-off. So far, it seems that good LEDs are decent in handling vibration. I haven’t noticed any kind of LEDs rated for rough service though I’ll admit to not searching them out. Heat is the bane of semiconductors whether from the environment or self-generated. If you can keep them from getting too toasty, they’ll give good service. Ventilation would help where possible. The only other minor drawback I can think of is that they will dim over usage time. After 10k hours (if they lasted that long), you’d notice the difference when changed out.

Author:	MariaB [ Wed Jun 01, 2022 4:27 pm ]
Post subject:	Re: 32V 250W locomotive headlight bulbs, again
Hi all, WB parts found these. PN:250P25-32V quoted price was $116 each.

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