Page 1 of 5 12345 LastLast
Results 1 to 10 of 45
  1. #1
    500+ This must be a daytime job Jackpilot's Avatar
    Join Date
    Dec 2005
    Location
    MONTREAL
    Posts
    930
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    working a real gauge without PMSys.



    (This works only with electrical gauges)
    Wired this way, the pointer moves from zero to full when the pot is rotated from zero to max.
    The pot can be preset so that the pointer goes to a target value when power is applied and reverts to zero when power is off.
    Can be used that way for brake pressure with a microswitch on the brakes pedal.

    Now the question !!
    What kind of little electonic circuit could be used so that the pointer would creep slowly to the target value when power is applied. Could be used for Hyd pressure on engine start, or APU spooling up, or temperature going up etc... No link with any software and sort of eye candy but good enough for secondary systems and dirt cheap!

    Any idea?
    Jackpilot
    B737-700 Posky
    FS9/P.Magenta
    without PMSystem

  2. Thanks W9XE/Project777 thanked for this post
  3. #2
    25+ Posting Member
    Join Date
    Dec 2007
    Location
    New Zealand
    Posts
    52
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    I get the feeling a dirty great electrolytic capacitor would be involved somehow - a smoothing cap from a power supply maybe? This is the kind of thing used to provide soft on-off functions on courtesy lights etc..

    Put the capacitor in parallel with the gauge and it would rise & fall slowly I think - though my analogue electronics skills are crude in the extreme and I would suggest waiting for confirmation / debunking of my theory..

    Cheers

    James
    CH Yoke
    CH Pedals
    2 Saitek TQ`s
    Opencockpits multiradio
    GF LGT + T8
    BU0386x and custom autopilot control panel
    Basic pedestal and mip for generic GA sim in progress..

  4. #3
    Executive Vice President, MyCockpit


    Matt Olieman's Avatar
    Join Date
    Oct 2005
    Location
    Ocala, FL USA
    Posts
    2,884
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Smile I know who has the answer :)

    This is a good one for Mike Powell I'm willing to bet he has the answer

    Matt Olieman

  5. #4
    500+ This must be a daytime job Jackpilot's Avatar
    Join Date
    Dec 2005
    Location
    MONTREAL
    Posts
    930
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Actually, was trying to get his attention...lol...
    James, I thought about the capacitor but as I remember these things accumulate and release in a burst....may I am wrong/rusted too! I'll try it tomorrow anyway...and report.
    Jackpilot
    B737-700 Posky
    FS9/P.Magenta
    without PMSystem

  6. #5
    1000+ Poster - Fantastic Contributor AndyT's Avatar
    Join Date
    Jun 2006
    Location
    Oahu, Hawaii
    Posts
    1,236
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    The curcuit will work as drawn as long as the power supply is exactly in the correct range for the guage. Otherwise, you are going to need to adjust it with resistors. You will also want a diode in there to prevent reversing the polarity by accident and blowing the guage and the rest of the circuit.
    God's in command, I'm just the Pilot.
    http://www.geocities.com/andytulenko/

  7. #6
    500+ This must be a daytime job Jackpilot's Avatar
    Join Date
    Dec 2005
    Location
    MONTREAL
    Posts
    930
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    It works, I actually tested it on a 747 Hyd pressure gauge.
    One AA 1.5v is enough. I tested up to 5v. The pot acts as a resistor itself and just needs a new adjustment to get the pointer where it should be when the voltage is increased.

    What I would really like is a progressive "spool up" like 3 seconds..in other words inserting an electronic circuit that would have the same effect as turning slowly the pot's shaft . In fact decreasing a resitor value slowly over a few seconds when power is applied and vice versa.
    Maybe a transistor can do that...my knowledge is insufficient!!
    Jackpilot
    B737-700 Posky
    FS9/P.Magenta
    without PMSystem

  8. #7
    300+ Forum Addict



    Join Date
    Feb 2007
    Location
    California, USA
    Posts
    380
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    I think we can come up with a simple circuit to do that. First I need to know something about the gauge sensitivity. Can you make some voltage and current measurements?

  9. #8
    500+ This must be a daytime job Jackpilot's Avatar
    Join Date
    Dec 2005
    Location
    MONTREAL
    Posts
    930
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Yes if you tell me how to do it...with a multimeter I suppose.
    I have two wires identified as + and - and three unknown ones.
    For the moment I power it with a 1.5v AA and it deflects fully with the pot half way.

    All ears.
    Jack
    Jackpilot
    B737-700 Posky
    FS9/P.Magenta
    without PMSystem

  10. #9
    300+ Forum Addict



    Join Date
    Feb 2007
    Location
    California, USA
    Posts
    380
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    I need the voltage across the gauge when the pot is set for full gauge deflection. This is done with the multi-meter leads plugged into the + and - jacks.

    I also need the current through the gauge with the pot set to get the same gauge needle deflection. For this you need to put the multimeter leads in series with the gauge. You may have to tweak the pot to get the same gauge deflection.

  11. #10
    500+ This must be a daytime job Jackpilot's Avatar
    Join Date
    Dec 2005
    Location
    MONTREAL
    Posts
    930
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    will do and report
    Thanks mike
    Jackpilot
    B737-700 Posky
    FS9/P.Magenta
    without PMSystem

Page 1 of 5 12345 LastLast

Similar Threads

  1. Latest picture and update on my real 727 engine gauges working
    By 737NUT in forum Interfacing Real Aviation Parts
    Replies: 11
    Last Post: 07-31-2011, 11:45 AM
  2. Real VSI+$40+1hour=Working real gauge!
    By 737NUT in forum Interfacing Real Aviation Parts
    Replies: 6
    Last Post: 01-11-2010, 01:35 PM
  3. AFT OVH - PMSys 122
    By Tony in forum PMSystems
    Replies: 9
    Last Post: 03-16-2009, 06:35 AM
  4. Real 1.5" yaw damper gauge
    By Jackpilot in forum General Builder Questions All Aircraft Types
    Replies: 8
    Last Post: 10-14-2008, 07:45 PM
  5. One CPU for FS9 + GC + CDU + MCP + pmSys + pmInst
    By Greg Kernaghan in forum PM General Q & A
    Replies: 4
    Last Post: 01-22-2006, 04:38 AM