AMX240 Questions

Hi Kent,

One other piece of information. If I pull the breaker on the lighting circuit (pin 7 voltage goes to 0) then the lights go full bright which is indicated in the manual. This seems to indicate the unit is wired correctly.

I even tried shorting the reostat so that pin 7 is getting the full 24 volts and bypassing the reostat completely. No change at all. Are you certain there is no configuration setting that enables the restate dimming?

Update: Avidyne tech support has reached out to PS Eng and they say that when they put a unit on their bench it works fine. I don't know if it is an AMX 240 or one of their units. I also don't know if it is wired exactly like how I have it on my bench or what. Or there is the possibility that I just have two defective units. 

Gring, 14 or 28V? Solid state or old style rheostat?

I just got off the phone with Gary at PS Engineering. Here’s who this unit works. Basically there are two brightness modes: day and night. When the signal to pin 7 is below about 1.5V the LEDs are at full bright. This is “day” mode. When the signal is above 1.5V the unit transitions to “night mode”. Night mode only has a control span of 1.5V to about 14V even with a 28V buss. In other words there is no increase in brightness between 14V and 28V. Also, maximum brightness in night mode is much less than the day mode brightness. You can see this illustrated in my bench test results. The audio panel draws 410mA in day mode. In night mode minimum (about 1.6V)  it draws 240mA and in night mode maximum (15V) it draws maybe 250 mA. The bottom line is there is a very narrow brightness adjustment for night mode, and max night brightness is nowhere near day brightness. In my case my rheostat has a control range of 15 - 28V so I am always in max night mode, but that brightness level is very dim and unreadable in the daytime. I need to look at my rheostat to see how I can get 0V when it is turned all the way up. Also I need to see how that is going to affect my CDI backlighting. All this brightness logic was determined by Avidyne and they make the front panel. PS only makes the guts. If I were Avidyne I would have increased the adjustability span in night mode so that 28V is at or close to full bright. This could be changed by firmware but that is not something a user could do since there is no way to update it in the field. 

Thanks Gring. The only remaining issue I have is my current rheostat starts off at 15V and goes to 28. Because the control span on the 240 is only 2-14V I don't really have any control My rheostat was designed for incandescent lamps so the 240 probably doesn't have enough load to bring to voltage down but I can always install a resistor. My rheostat also does't have the detent where it is basically off so I don't have that full bright setting. I need to replace it and hopefully that will fix the problem. My only beef is I wish Avidyne would have published the fine details on how the lighting works. That would have saved everyone (including their tech support) a lot of time.