[simpits-tech] 5v AC for lighting?

[dabigboy at cox.net]

---- Gene Buckle <geneb at deltasoft.com> wrote: 
> On Fri, 2 Mar 2012, dabigboy at cox.net wrote:
> 
> Matt, unless there is specific circuitry between the power input and the 
> lamp that _requires_ AC, you can run them on 5v DC with no problems. 
> Bulbs don't care about ac/dc.  LEDs on the other hand _require_ DC.

Awesome, I will give it a shot then. I did try 5v DC on my Gables navcom, and nothing happened....perhaps I missed a pin or something (this was before I hackerized the connector), or maybe the weak adapter I was using did not deliver sufficient current.

> Note that aircraft panel lighting systems are dimmable by using a variable 
> transformer that takes 28v AC @400Hz in and can output 0..5V AC out.

That would explain why all my diagrams and placards on radios etc indicate 5v AC needed for lighting. So what happens if I just vary DC voltage? Nothing?

Matt