* Who's Online

  • Dot Guests: 19
  • Dot Hidden: 0
  • Dot Users: 5
  • Dot Users Online:

* Recent Topics/Posts

Help for PCU-15A/P Torso Harness by bluc69
[Today at 05:00:39 PM]

Grimes LG light wiring by dkm
[Today at 04:28:50 PM]

FNG intro, bought Feather's Trainer by Nigel
[Today at 04:24:13 PM]

Attaching FLCS POWER TEST grime light to AIC by Nigel
[Today at 03:55:37 PM]

CNC Backlight PCB's by JCook
[Today at 03:46:28 PM]

Pitmeeting Twente 2014 by Rufus
[Today at 02:37:13 PM]

A day like today by Nikolas_A
[Today at 02:08:02 PM]

DZUS fastener GROUP BUY (2014) by Chain
[Today at 01:52:03 PM]

Hornet's New Digital Display by powers
[Today at 12:41:35 PM]

starting my seat! by Nigel
[Today at 12:22:59 PM]

eBay heads-up by ulti
[Today at 11:59:00 AM]

Jumping into a F16 cockpit by ReaperAT
[Today at 08:44:39 AM]

PSCOCKPIT SYSTEM 3rd RUN! by funkster
[Today at 02:23:56 AM]

Cougars programming by sagrzmnky
[April 22, 2014, 11:16:36 PM]

F-16 A/B Flight Manual Lockheed Martin by JJ
[April 22, 2014, 04:57:28 PM]

one of two Xkeys not recognized; neither in Falcas memory Resident Mode software by Focaldesign
[April 22, 2014, 03:26:30 PM]

Pictures cockpit left back wall by Nigel
[April 22, 2014, 01:11:25 PM]

Best way of mounting Brenda's ACES II Seat? by Nigel
[April 22, 2014, 01:09:11 PM]

KK's Pit by KK
[April 22, 2014, 12:20:19 PM]

Happy Easter! by Wolverine
[April 22, 2014, 11:19:25 AM]

Author Topic: Negative voltage at AIC backlight?  (Read 1805 times)

Offline Rufus

  • General
  • ******
  • Join Date: Feb 2012
  • Location: California
  • Posts: 1072
  • Country: us
Re: Negative voltage at AIC backlight?
« Reply #60 on: December 23, 2013, 02:11:22 AM »
Ok...I think I've noodled something out about the Mean Well supply.  I went back and looked at the block diagram again, and it appears that while the G/G (COM, in the diagram) and mains earth may not be directly tied together they are internally shared somehow - with with a capacitor between the high side and mains earth presumably to create some delay/over voltage protection for given channels.  But it looks as if the circuit branches are self-draining at shut down, so nothing to worry about there.

I'm thinking though that I shouldn't ground my pit structure to/through the supply earth though, because a back EMF could harm the protective capacitors...but that I can use the wall plug ground over a separate cord with only the ground wire connected?  I'd lift this circuit with a relay at MAIN POWER - other than OFF, maybe with a slight delay.
- Rufus

Offline Cupra

  • General
  • ******
  • Join Date: Jun 2009
  • Location: Solothurn
  • Posts: 715
  • Country: ch
    • 1st VFW "Glory Wings"
Re: Negative voltage at AIC backlight?
« Reply #61 on: December 23, 2013, 02:17:28 AM »
Oops, that has gone under... or how ever you say  :harhar:

Yes, everything else is working without anny issues. Boards are dedected and at the power supply Pins of the boards the +12V DC is stable with the Switch on and it is 0,00 when the Switch is off.
The exact same circuit (a second one) is connectet to the backlight-connectors and there I have the -14V when i Switch off. But bowth funktions are working without problems or thermal abnormalities.
So for me I would say if eveything works proper there is no Need to do anything... I am just always a litte afraid if I have voltages I canīt explain  :notes: