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Re: Interior Light Question

Posted: Sun Nov 19, 2017 10:33 pm
by 170C
Thanks for the reply George (and Bruce). I misspoke regarding my overhead led's not being dimmable :oops: I think I purchased all of my led bulbs from the same source as George. What I forgot was that when a sizable rewiring project was being done a number of years ago, my IA didn't connect the overhead lights to the instrument rheostat. That could easily be corrected, but since I don't fly at night, unless I unexpectedly get caught trying to get somewhere, its not an issue. I have turned them on several times in early morning flights where it was very cloudy or arriving late in the day with the same conditions and they do a good job of illuminating the instrument panel. Sometimes my head will be in the way for the far left side of the panel, but the two map lights (led's) light it well. So--my led overhead's may, in fact, be dimmable. A number of other Cessna owners have seen my setup and have duplicated George's system.

Re: Interior Light Question

Posted: Wed Nov 04, 2020 1:34 am
by GAHorn
Bruce Fenstermacher wrote:So the LED that George bought is not just an LED it us an LED with a dimming circuit as I described. Amazing how small these circuits gave become. 20 years ago the 555 timing chip alone was as big as your finger nail.
Well, this is years later as I reviewed this topic... and just to be clear... the LEDs do not contain a separate dimming circuit. They are described by their mfr’r as being “dimmable”.

Re: Interior Light Question

Posted: Wed Nov 04, 2020 2:47 am
by Kyle Wolfe
George, when/if you pull the false instrument panel would you grab a few pictures of the lights and the plug in setup? Thanks!

Re: Interior Light Question

Posted: Wed Nov 04, 2020 5:53 pm
by GAHorn
Kyle Wolfe wrote:George, when/if you pull the false instrument panel would you grab a few pictures of the lights and the plug in setup? Thanks!

Kyle, I have spanked myself several times for not taking pics when I did that mod. I can tell you, it’s not exactly a “work of art” to view.
But let me describe it in more detail:

I used 24 ga wire, twisted (such as when wiring a mag compass lighting) to avoid magnetic influence upon my panel-mounted mag compass.

I gang-soldered the GOR lamps to that twisted harness and insulated it with heat-shrink at the soldered connections.

Laying the false-panel upon my work table (Jamie fussed at me for using her kitchen for this project)... I routed the twisted wire pair around the backside of the panel and attached it every few inches using a hot-glue gun. At EACH instrument opening, arcing across the top of the opening, I installed the GOR lamps oriented Down so as to shed their light upon the instrument.. gluing each lamp by it’s twisted-wire to the panel. (Do not allow the hot-glue to contact the lamp itself.). The 3-1/8” gauges each got a triple-set of lamps about 1/2” apart around the circumference of the opening. The 2” instruments rec’d 2 lamps each. (This cut in-half the load thru each fuse...or said otherwise, doubled the protection for the circuit.)

I actually “split” the lighting into 2 circuits so as to reduce the possibility that a 1A fuse would blow in either 24 ga. circuit, and also to provide redundancy. I used a 1A in-line fuse for each.

I brought the long, twisted harness I’d made to telephone “modular” plugs so as to allow the circuits to be unplugged for the panel to be detached for maintenance. (In case I needed to remove the altimeter for recertification or replace a gyro, etc.) The telephone modular cord is also 24 ga and is the same as used on a typical ELT remote switch panel, so I had no qualms about using that method. The electrical draw/load is quite small (don’t recall the exact amount) but I tested it and found a 1A fuse would support it without “blowing”, and I wired it up in parallel to the overhead Grimes “torpedo” that Cessna provided for direct-instrument lighting.

The two modular plugs are connected to the output terminal of rheostat that controls the original overhead Grimes torpedoes.

Do NOT install any GOR lamps below instruments...only above them... or you will encounter glare as the light reflects off the instrument glass.

I have had absolutely NO problems with this system and No lamp failures. (They are rated for 20,000 hrs according to their supplier.)

Hope this helps.

Re: Interior Light Question

Posted: Sun Nov 08, 2020 4:13 pm
by Kyle Wolfe
Thanks George!

Just clarifying, you used separate lights like these https://www.parts-express.com/12-volt-w ... N0EALw_wcB and not a string of rope lights ?

Re: Interior Light Question

Posted: Sun Nov 08, 2020 11:13 pm
by GAHorn
Kyle Wolfe wrote:Thanks George!

Just clarifying, you used separate lights like these https://www.parts-express.com/12-volt-w ... N0EALw_wcB and not a string of rope lights ?
No. What I use were incandescent lamps intended for model railroading.... because they will definitely be DIMMABLE....and they are not polarity-sensitive.
https://www.micromark.com/Grain-of-Rice ... kage-of-40

Re: Interior Light Question

Posted: Tue Aug 02, 2022 9:51 pm
by rnealon1
Tagging onto an old thread, looking for a replacement for the dome light cover '54 170B IPC Part Number 0710101-1. Mine is plastic and looks like this:
Screenshot_20220802-173359_Photos~2.jpg
A search of the part number turns up this which looks the same but is listed for a 180 through 182A and lacks the screw holes in the center:
20201207_073853__79254.jpg
20201207_073853__79254.jpg (10.06 KiB) Viewed 5440 times
There is also a salvage part online which looks aluminum, has the screw holes, but is listed for a 172/180:
C6F6985E-3375-4996-A4B7-9F78BD46DB34.jpeg
C6F6985E-3375-4996-A4B7-9F78BD46DB34.jpeg (19.07 KiB) Viewed 5440 times
Anyone have a source for this dome light cover?

Thanks,

Bob

Re: Interior Light Question

Posted: Wed Aug 03, 2022 12:35 am
by GAHorn
You can add the screw holes in the 182 part. :wink: