External Dimmer Pin 25 and 26

[dynonsupport]

SkyView cannot use a PWM input to dim the screen. It must be a DC voltage. I don't know what the Garmin GTN or SL-15 expect.

You cannot use a 10 ohm potentiometer across your aircraft bus as we mentioned last week. You can use a 1K Ohm or greater potentiometer to create this voltage.

As the manual says, the DIM OUT is limited to 120mA, You will need to look up the specs on your switches and determine if the max load is greater than this. If it is greater than 120mA, you need to use an external dimmer, or an amplifier like Vern described. We haven't evaluated Vern's solution to the level that we can say it will or won't work, but he's a smart guy.

There are PWM dimmers that take an analog voltage input to drive the dimmer. This voltage could be split to your various instruments as well as your panel LEDs.

Note that this support forum is not staffed 24/7, and a question asked on a Thursday evening will sometimes not get a response by Dynon until the next week, especially with questions that require some deeper engineering to be done. We responded with the section of the manual asking what was not clear because your previous statement was "the text of the manual is not clear enough for me to understand the system" so we were focusing on improving our manuals to be clearer to all. We're sorry if that came off as dismissive.

Here are some previous threads on using SkyView to dim an LED or using an external pot to dim SkyView:

http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1348497651

http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1345262945

http://forums.matronics.com/viewtopic.php?p=465847&sid=c37f9600206e808732716f6f37dd3928

 

[swatson999]

Yeah, okay, whatever...you've been given the answers to your questions numerous times, and referred to the Installation Manual, which also has them, and somehow that's Dynon's fault? Or our fault?

 

[Dynon101]

Dynon,

Thank you for your answer...very informative and helpful.

I apologize that this thread became abrasive and that I was impatient. I am really making progress on this build and my days off are limited however I am making progress. The Dynon systems are getting very advanced and with that success there are a great deal more users and that produces a bunch of "needy" questions like I have posted however I do appreciate and am grateful for your help!!!

 

[mmarien]

I'd like to thank HomeBuilt101 for asking the question, Vern for supplying an answer and Dynon for having the foresight to build the function into the Skyview.

I had the panel out for other things so I built a gizmo according to Vern's instructions. I have eleven RockRack switches that draw 180 mA and a LED strip that draws 270 mA. More than the 120mA that Skyview will handle. I used a TIP32C PNP transistor (~3A). It draws about 3 mA at the BASE with a full load. Skyview should have no problem handling that on pin c37p26.

I purchased the SV-KNOB-DIMMER for the input on pin c37p25. I also spliced in my radio and xponder to the DIMMER output. The whole frigging panel dims when I turn the knob. No smoke either

The gizmo was easy to make. I just crimped dsub pins to the transistor and covered it with a case. No soldering involved. I used another dsub to wire it to Skyview pin c37p26 (BASE), GND (COLLECTOR) and the ground leads of my LED's (EMITTER).

 

[mrdaud]

mmarien - Nicely done!

 

[N21HV]

I had a variant of this challenge in that I wanted to dim the LEDs in the annunciator panel and also a string of LEDs I used as panel lighting that is embedded in the glare shield above the panel along with the Dynon screen. An issue I ran into was that while Dynon expected low-side switched current sink, my panel and annunciator expected a high-side switched voltage source. So, I made a little "gender bender" board that uses opto-isolator as the switch that triggers N-channel MOSFET that can source up to 5A of load. Now, the entire panel lighting, annunciation, and indicators dim along with the Dynon screen and is controlled by a single pot on the annunciator panel. Couple issues, though. My Garmin GPS and GRT backup EFIS do not dim along with everything else<g>.

Hiroo

 

[mmarien]

Couple issues, though.  My Garmin GPS and GRT backup EFIS do not dim along with everything else

Same here. My GPS495 doesn't dim although it changes to night mode. Not really a panel device though.