What Should The Power Source Be For Remote Dimmer

Dynon101

I love flying!<br />
Joined
Mar 5, 2016
Messages
382
I am starting a different thread for this specific topic (I still need the other thread's questions answered).

I think careful thought must be given to the feed source of the Dynon remote dimmer...perhaps everyone has been down this road but it is new to me.

Pin 25 needs to see a regular, old, boring 0 to 30 VDC signal (0 to 14 VDC in my airplane).

For this signal, I need to tap off of an always hot, protected 14 VDC wire.

I am considering tapping off of one of the CBs that provides the power feed to the Dynon.

If I used another source (such as a misc interior light feed wire or a landing light feed wire) and should that devices CB pop then I do not have any remote dimmer control of the Dynon and if pin 25 sees 0 VDC then it will go to minimum brightness. That could be bad because in in bright daylight conditions then I could not go into the menu and select the internal dimmer control. Is that accurate?

Is tapping off of the Dynon power feed CD what you would recommend for the power source for this remote dimmer circuit?

Naturally there is a load associated with the variable resistance of the rheostat/potentiometer however I am not able to calculate that load. The Dynon CB is only 5 AMPS so I do not want to tax the CB with this additional load.

A possible negative to using the same CB to power the dimmer is I am now introducing another possible failure point.

The SV has TWO CBs that provide power, if one CB pops because of a short on my dimmer circuit then will the second CB be able to power the SV system?

I do not think it necessary to run a completely different CB for this dimmer circuit...or do I?!?!?

If I install a potentiometer, I think I will need to run that feed wire to lug #3 of a potentiometer and then connect lug #1 to ground. The center lug (wiper) will go to pin 25. Is the electrical path of my thinking correct?

Any advice would be GREATLY APPRECIATED!!!
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
1) You cannot externally dim significantly below the light sensor value. So if you request zero brightness but the light sensor sees a bunch of light, it won't go full dim. Hence, the failure of the power source for the dimmer is not catastrophic. You can then manually go into configuration and switch to internal dimming if needed.

2) A properly chosen potentiometer draws less than 10mA (0.01A) and is thus completely trivial in current calculations.

3) We'd highly recommend you buy Dynon's Dimmer module and just follow the instructions on page 15-4 of the install manual to hook it up.

http://dynonstore.com/#!/SkyView-Dimmer-Module/p/69175457
 

Dynon101

I love flying!<br />
Joined
Mar 5, 2016
Messages
382
Thanks...I do appreciate that you at Dynon have engineered a well thought out product. THANKS AGAIN!!!
 
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