Bulb intensity

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Dave Taylor
Looking at the two 28V options, is it possible to say which bulb will be more 'dimmable'?
Having trouble getting the panel backlit switches 'less bright'. Right now, they are crazy bright and when dimmed, the blink off before getting to an acceptable 'dimness'.
(Was thinking of taking the LEDs out for these incandescents)
These are 13 Honeywell AML series rocker switches with one internal bulb, all on what looks like a (single) rheostat.
 

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Put higher wattage bulbs in.....
 
LED bulbs are tricky to dim on a nice linear scale, the supply must be designed with the exact LED in mind. normal bulbs on the other hand are very easy to dim, they follow ohms law. simply a higher wattage bulb will start out brighter.

bob
 
Dimmers designed to work for high wattage incandescent bulbs may not always work with LEDs, so you’ll have to get one designed for the bulb you’ll be working with. One thing to check into is a pulse width modulation (PWM), which causes the LED to flicker on and off at a high rate that is undetectable to the human eye, so you can set the PWM to a certain rate depending on how bright or soft you want the bulb to burn.

Once you make the switch to LED, you won’t go back. Funny this topic came up, because we’re installing new entry way light fixtures today in the house. Trying out the ‘new’ style LED candelabra bulbs. Surprisingly, they put out an impressive amount of light and they look pretty neat too.
 
I wasn't clear.
I am removing the LEDs
I am 'going back' to incandescents.

Which of the two bulbs in the pdf would be best?
Unit74 and unsafervguy say the higher wattage bulbs.

That sounds like the 17 bulb; the higher amp draw 0.065 vs 0.040 for the 85 bulb.
Even though the lumens for the 17 bulbs is >2x higher?

Thanks
 
You are driver a higher wattage bulb on the same voltage-- Lower lumen output. Think big hose little hose on the same pressure.
 
Looking at the two 28V options, is it possible to say which bulb will be more 'dimmable'?
Having trouble getting the panel backlit switches 'less bright'. Right now, they are crazy bright and when dimmed, the blink off before getting to an acceptable 'dimness'.
(Was thinking of taking the LEDs out for these incandescents)
These are 13 Honeywell AML series rocker switches with one internal bulb, all on what looks like a (single) rheostat.

You aren't REALLY talking about going back to incandescent bulbs, are you? You'd be a darned fool for doing that, but then again, I make some of my living cleaning up damfool problems.

Now, you say that they blink before going off. Something is crazy wrong in the dimmer circuit. The only time LEDs blink is if somehow the dimmer is one leg of a relaxation oscillator circuit.

Jim
 
I saw an experimental Zentih 750 with something like this on it as a landing light. 15,000 lumens, draws a lot of wattage off the battery. The use was night time bush landings, which never struck me as a particularly good idea. Although the argument could be made that with this much light, it wasn't really night.

timthumb.jpg
 
LED bulbs are tricky to dim on a nice linear scale, the supply must be designed with the exact LED in mind. normal bulbs on the other hand are very easy to dim, they follow ohms law. simply a higher wattage bulb will start out brighter.

bob

No, they do NOT follow Ohm's law. They follow an inverse square law. Ohm requires that the bulbs be of constant resistance. Last time I looked, incandescents using tungsten filaments follow a positive temperature coefficient law.

LEDs are trivial to dim properly. But you have to remember that they follow a CURRENT proportional to brightness, not a VOLTAGE proportional to brightness.

Jim
Dimmers designed to work for high wattage incandescent bulbs may not always work with LEDs, so you’ll have to get one designed for the bulb you’ll be working with. One thing to check into is a pulse width modulation (PWM), which causes the LED to flicker on and off at a high rate that is undetectable to the human eye, so you can set the PWM to a certain rate depending on how bright or soft you want the bulb to burn.

Once you make the switch to LED, you won’t go back. Funny this topic came up, because we’re installing new entry way light fixtures today in the house. Trying out the ‘new’ style LED candelabra bulbs. Surprisingly, they put out an impressive amount of light and they look pretty neat too.

The eye is a peak detecting device. LEDs are microsecond instantaneous responders to PWM. It is peak brightness or nothing at all (and a very narrow range that the LED will force the PWM into low frequency oscillation if not properly designed). Which is what the OP described. PWM does NOT work on LEDs.

OP, you say a "rheostat" (archaic word) works as a dimmer. Is there electronics between the potentiometer and the bulbs?
 
I have a bunch of Honeywell AML rockers in my plane. I have the LEDs and I dim them (works okay).

However, the biggest problem is getting the bulbs to 'seat' securely so they don't blink on and off due to vibration. It seems to be a problem shared by the incandescent and LED bulbs; the lamp design is not vibration tolerant.

So I'm curious - have you flown with them? Do you problems with getting the bulbs securely seated?
 
Bill. That is interesting because I talked to HW about my switches. The techie said "you can't replace those bulbs, they're soldered in!"
After discussing it further it seems the newer ones are soldered. Ours (yours and mine) are push-in bulbs.
Now. I wonder why they switched to soldered? is what I was thinking at the time.
You have answered it.
My first night flight in this plane- tonight, no blinking of the lights, maybe I'll be lucky.
 
Bill. That is interesting because I talked to HW about my switches. The techie said "you can't replace those bulbs, they're soldered in!"
After discussing it further it seems the newer ones are soldered. Ours (yours and mine) are push-in bulbs.
Now. I wonder why they switched to soldered? is what I was thinking at the time.
You have answered it.
My first night flight in this plane- tonight, no blinking of the lights, maybe I'll be lucky.

Interesting. The only way soldered makes sense is with LEDs.

Coincidental with this thread,my switch lights stopped working completely. The fact that I’m doing a panel upgrade notwithstanding. I’d swap switches but now... more work req’d. ‍♂️♂️


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The final result in this issue was that I bought some ridiculously inexpensive incandescents from 1000bulbs.com
SKU# IND-0085-10PK
And I could not be happier; the switches are now all uniform brightness. They all dim evenly. They all dim way down so that the cockpit is not ablaze with horrid white light.
 
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