External Dimmer for Skyview Display - recommended fuse size

[RV Triumph1974]

I am going to repurpose a baggage light dimmer switch (0 to 12 volts variability) to control the brightness of the Skyview display, as I find the night time control of the screen brightness is way to clunky to control as it is currently. Question is for those that have done this where the power is a dedicated circuit off the main bus (not shared power from the Dynon), what fuse size is recommended? My wire size will handle the 5A amp that the main sky view display has, but suspect the screen display power going into Pin 25 could be a little lower amperage fuse and may offer better protection if at 2 or 3 amp vs. the 5 amp used for the entire Skyview?

Thanks!

 

[Rhino]

You don't necessarily need one. Pins 1 and 20 on the HDX provide power for a dimmer knob, so you don't need a fuse if you use that as your power source. It's already fused going into the HDX. Look up the wiring for the SV-KNOB-DIMMER in the installation manual.

 

[Rhino]

You might also want to look at this:

SV-KNOB-DIMMER Questions

I cannot see my screen at night as it is too dim. I need to use an external dimmer as described in installation manual on pgs . But I have a Rutan Long EZ, with very limited panel space, so first question is how big is the SV-KNOB-DIMMER? Is it the same size as the other panels, like intercom...

forum.flydynon.com

If your baggage light dimmer is a rheostat, you might not want to use it.

But to answer the original question, if you use a power source other than the pins on the HDX, 5 amps should be fine. That power isn't used to power any lights. It only provides a reference voltage to the HDX, so the HDX can set the dimming level accordingly.

 

[RV Triumph1974]

Thanks for the comments and info - very helpful. I have the original classic sky view - so any thoughts on to why a rheostat may not be a good idea? At least I think my dimmer may be a traditional rheostat...will have to see if I can find the documentation on that.

On a side note: - has anyone been able to set the "automatic" Parmerters values so that the screen is visible at night? If so, what settings seem to workout ok?

 

[maartenversteeg]

Note that the Skyview really doesn't need a rheostat, just a variable resistance resulting in a variable voltage control towards the Skyview is all that is needed. The external control is just a 10 kohm variable resistance that is connected between gnd and 12 Volt and the variable output voltage really doesn't draw any current. A rheostat might be much too coarse. You could use any variable resistor and just need s space for a single (tiny) know on the panel, but if you want to use the Dynon provided dimmer 'module' it is only about 20 x 40 mm in size.

 

[Rhino]

Thanks for the comments and info - very helpful. I have the original classic sky view - so any thoughts on to why a rheostat may not be a good idea? At least I think my dimmer may be a traditional rheostat...will have to see if I can find the documentation on that.

No difference with the Classic. Using rheostats was discussed in that thread I linked. They'll probably work, but the results may not be as good. As maartenversteeg noted, you can use the SV-KNOB-DIMMER for this purpose. But it costs more. The member in that other thread didn't use it because his panel space was extremely limited, so even the SV-KNOB-DIMMER wasn't suitable. Plus, it cost him a lot less to use his own potentiometer.