Panel lighting

[xcrmckenna]

I would like to upgrade my glare shield light strip and add some Nulite or UMA instrument lighting. Has anyone installed this led red and white strip and dimmer? Or are these legal in certified planes? I haven’t heard back from my avionics tech if they are or not.

 

 

 

https://www.aircraftspruce.com/catalog/elpages/dualchannelpwm.php

 

 

 

https://www.aircraftspruce.com/catalog/inpages/flexibleLED_red12.php

 

Or any other lighting suggestions?

 

 

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[Guitarmaster]

The LED strip lights okay. You can see the top instruments fine, but the bottom ones are really tough.
I had the fiber lights in my Mooney and absolutely love them. They will be going in my 310.
I have looked for all kinds of ways to light the cockpit inexpensively, but really have found none that are worth pursuing.

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[RLCarter]

 

[Yetti]

Someone mentioned that glare shields in various models are different lengths.  Which would impact how much light would be cast on the bottom instruments.   On my F there is are bulbs and lenses on the far left side that sticks out a bit and probably shoots lights on the bottom instruments.   I think the lenses in the Mooney glare shield focus the light.   The strip leds you posted  probably are not a focused LEDs.   But you can get focused LEDs.    As far as legality we are probably somewhere around the legality of LED PAR 46 tractor bulbs replacing landing lights.   Replacing the transistor with PWM like you posted is probably smart.   You can get the same PWM on amazon for $15.00    I think you would find you could put all three panel light circuits on one PWM module. I think the bulbs are the little GE bulbs which probably have a LED replacement, but you would need dimming and probably need to use a PWM on them.   Your IA is a guide to what he/she is comfortable signing off on.   Ya I want to do mine to.   They are flakey and I have had to use the eyeball light a couple times.

[RLCarter]

@Yetti is correct, I ended up fabricating an ABS plastic glare shield to replace the worthless pad that sticks past the instrument panel to get lighting to the bottom of the panel.....legal? I doubt it, but I have full panel lighting which to me is a safety benefit 

[MikeOH]

As an EE I have to pipe in about PWMs vs. the stock dimming transistor.  While very inefficient the transistor is virtually noise free (electrically); it ends up being like a rheostat and just dissipates power.  PWMs can be quite tricky to design with low noise onto both their outputs as well as injecting noise back into the aircraft's power.  I'd be REALLY careful with a low-cost PWM.  YMMV.

[ArtVandelay]

I use a combination, regular white lights on the side, with pilot side side piece removed (I think that’s what [mention=12701]RLCarter[/mention] was referring to) and red LEDs on top. With modern radio stack avionics having own backlighting there isn’t a need for much extra light. I used LED bulbs so I didn’t have to alter the glare shield wiring.

 

 

Tom

 

 

 

[jamesm]

Interesting placement of the standby "whiskey" compass.  I like it.

I am always looking for practical ways of maximizing panel space.

Do you get any magnetic interference?

Did you swing the compass after the  relocation?

[carusoam]

James, while you wait...

some notes on the panel mount compass... can be found in a few threads...

https://mooneyspace.com/search/?q="Panel mount compass"&updated_after=any&sortby=relevancy

Best regards,

-a-

[ShuRugal]

As an EE I have to pipe in about PWMs vs. the stock dimming transistor.  While very inefficient the transistor is virtually noise free (electrically); it ends up being like a rheostat and just dissipates power.  PWMs can be quite tricky to design with low noise onto both their outputs as well as injecting noise back into the aircraft's power.  I'd be REALLY careful with a low-cost PWM.  YMMV.

If you're really worried about a PWM supply sending noise back into your system, you can tie an electrolytic cap across the inputs. This is standard practice in RC speed controllers to keep the PWM spikey back emf from killing things.

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[MikeOH]

12 hours ago, ShuRugal said:

If you're really worried about a PWM supply sending noise back into your system, you can tie an electrolytic cap across the inputs. This is standard practice in RC speed controllers to keep the PWM spikey back emf from killing things.

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While a cap can help, proper filtering of EMI is more complicated than that.  Further, electrolytics are a sub-optimal choice; not effective for high frequencies and less reliable than other types.  Thing is, interference from a noise source like a PWM can be subtle and may not be present in all conditions (e.g., some comm frequencies might be affected, not others; autopilot 'glitch,' etc.).

[NicoN]

May I ask whether the typical LED-Stripes are dimmable with the Rheostats we have in our Mooneys?

I am thinking of pieces of RGBW-Stripes and connect the White and the red control line to the Rheostats.

 

 

 

[Marauder]

May I ask whether the typical LED-Stripes are dimmable with the Rheostats we have in our Mooneys?
I am thinking of pieces of RGBW-Stripes and connect the White and the red control line to the Rheostats.
 
 
 

I couldn’t get them to work correctly with the factory rheostat. I used a PWM controller. Make sure you are using a dimmable set of LEDs.


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[EricJ]

7 hours ago, NicoN said:

May I ask whether the typical LED-Stripes are dimmable with the Rheostats we have in our Mooneys?

I am thinking of pieces of RGBW-Stripes and connect the White and the red control line to the Rheostats.

An incandescent bulb radiates light (and heat) proportional to the amount of power it consumes, so if the source voltage is held constant a rheostat in series will just turn the current up and down, turning the light up and down with it.

LEDs don't work like that.   Once they're forward-biased, i.e., conducting, they're "on" and radiating light.   Turning up or down the voltage or current doesn't have much effect in a practical application.   The way to "dim" an LED and is to turn if off periodically, and adjust the duty cycle of how long it is on during each period.   In other words, turn it on every 10 ms and turning it off in 5 ms will give it a 50% duty cycle, i.e., it'll be off half the time and radiating half the light that it would if it were on constantly.   Switching it faster than about 50-60Hz makes the switching invisible to the human eye and you just see the reduction in light, dimming, instead.    So the PWM, Pulse-width modulation, just adjusts the duty cycle between 0-100% for adjustment from off to full bright.

So switching from a rheostat-dimmed incandescent lamp to an LED also requires replacing the dimmer circuit with a PWM modulator or something similar.    The "dimmable" LED bulbs you can buy for your house have the PWM circuit built into the base, controlled by sensing the input voltage that is controlled by the conventional dimmer (rheostat).   Some of the fancier bulb replacements have something similar, but it makes the light more expensive and they sometimes don't work as well as the original incandescent bulb.

 

[TX-Champ]

Another option is here:  https://www.pilotlights.net/led-light-strips-light-channel-high-output-directional-led-12vdc-or-24vdc

Regarding LED lighting and dimmers, most hi power LEDs are best controlled by PWM as others pointed out. They will dim with resistive dimmers like those in older aircraft but with some limitations. High power LEDs have a minimum operating voltage that impacts performance.  When a resistive dimmers drops the voltage to about 9V, they’ll flicker and turn off. That’s usually around 40% or so of the LED output. In some case that works out OK. The only way to know for sure is to try the LED strip with your existing dimmer. If it doesn’t meet your needs you can change out the dimmer. 
 

 

[xcrmckenna]

Another option is here:  https://www.pilotlights.net/led-light-strips-light-channel-high-output-directional-led-12vdc-or-24vdc
Regarding LED lighting and dimmers, most hi power LEDs are best controlled by PWM as others pointed out. They will dim with resistive dimmers like those in older aircraft but with some limitations. High power LEDs have a minimum operating voltage that impacts performance.  When a resistive dimmers drops the voltage to about 9V, they’ll flicker and turn off. That’s usually around 40% or so of the LED output. In some case that works out OK. The only way to know for sure is to try the LED strip with your existing dimmer. If it doesn’t meet your needs you can change out the dimmer. 
 
 

Those look nice!


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[bradp]

Charles I got a max dim.  I actually recently found a dual max dim on Texas air salvage for about 30% of the cost of new.

Here's one from a PA-28R

https://www.texasairsalvage.com/main_view.php?editid1=216423