Hey guys, would like a bit o' help for automotive project.

Discussion in 'The Projects Forum' started by Neo1130, Sep 3, 2007.

  1. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
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    I own a 2005 Dodge Magnum R/T and am trying to figure out how to disable the ESP... There is already a device out there but it is $50 but I would like to make my own from scratch and learn how it works... But there are so many timing circuits out there that I am just getting lost... The thing I am refering it is at www.noesp.com.

    BASICLY, I would like to be able to turn off my ESP FULLY, not just 50%... I would like to be able to do it by pushing the button for roughly 5 seconds and letting go... This would energize a relay and keep it closed until I take away the power by shutting the car down... Please visit the website to see what I am talking about...
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    What are the safety risks associated with defeating the ESP on such a vehicle?

    hgmjr
     
  3. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
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    See that is the thing... I will only use it during track days when I am racing... On the streets it will not come off... It basicly gets rid of the "nanny" behind the wheel and will let you do what you inteded to do with the car...

    Hahaha, just so you know... This is probably one of the weaker cars I have owned so it isn't like I am not experieced... But then again, stuff happens to even the most experienced people...
     
  4. Dave

    Retired Moderator

    Nov 17, 2003
    6,960
    144
    No being an expert in what ESP is, or indeed what it does, but knowing that it is there for safety purposes, I would like to alert you to the disclaimer here at this site in light of the fact that you may not know what you are doing:

    Should you end up on the Darwin Awards, I would like to make sure you know what you are getting yourself in for and where we stand, should the worse happen!

    Dave
     
  5. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    I know fully well what I am doing... I have been racing vehicles for quite a number of years now and the new vehicle that I would like to race has too many electronics holding it back. As I stated before, there is already a mod that does this out there, I just want to create one from scratch... ESP is an electronic stability program in the Dodge Magnums that controls wheel speed in order to keep the car on the path of what the car THINKS you want to keep it at... If your rear starts to slide from underneath of you, it will apply brakes to compensate for that... This slows you down on the track... As I stated, it will be for track use only and not on publics roads... I did however find some more information that will greatly help out...

    The factory switch is a SPST momentary pushbutton switch. It is tied into ~5VDC and ground... When you momentarly hit the button for a second or two it will disable the ESP only PARTIALLY.

    What I want out of the system is to be able to push a button, hold it for ~5 seconds and have it kick in a relay that is NC, switch open the circuit until I shut the car off... The signal that I am trying to interrupt is roughly 12V... I basicly want it to be a multipurpose SPST switch... Have it do it's "factory" duty with a momentary push of the button AND when I want, hold for 5 seconds to activate a secondary circuit... Everything that I see out there takes the signal from the switch and just waits 5 seconds... I don't want a delay per se... I hope I am explaining this right... I just am unsure of how I would have the circuit recognize 5 seconds and then activate the relay...
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    I haven't the faintest of how the various control modules in the car interact together. The pushbutton you mention sounds as if it sends a signal into the control module and causes the program running in it to behave differently for a short time. Your relay sounds as if it would pull power to the whole module, and could cause some really unexpected side effects, besides a check engine light.

    Without knowing just how tightly integrated this control module is to the car's computer, it's pretty unwise to just cut the thing out - electronically speaking - and hope no negative effects will follow. Isn't there some racing literature that addresses this stability control - and perhaps has a working solution to the problem?
     
  7. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    If you guys could please read the link and find that what I am trying to do has already been done with no side effects... I just want a circuit that will energize a relay after 5 seconds of holding a button... There will be no CEL, nor problems with me driving the car... Also, please read the first post in the link I am providing... It is doing the SAME thing I want, only I would want it to run like I am asking... That switch will take place by a relay and the relay will be activated by a 5 second push and hold type button...

    http://www.lxforums.com/board/showthread.php?t=45309
     
  8. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    Can this be done with an RC circuit? If so, how would I tell the circuit to keep the relay energized?
     
  9. RiJoRI

    Well-Known Member

    Aug 15, 2007
    536
    26
    Personally, I'd probably use a toggle switch in place of the relay.
    However, given the design requirements, and the idea of RC timing, I'd feed the output of the RC portion into a comparator, and latch the output using feedback -- either feedback into the comparator's input, or feedback using a double-pole relay (one pole controls the bypass activity, the other is used to feed power to the coil of the relay).

    As I remember from tech school, it takes 5 times R*C to get C to ~100% of the voltage. So using the voltage and current calculations at http://www.allaboutcircuits.com/vol_1/chpt_16/4.html and the components listed (10K resistor and 100uF cap), it should take 5 seconds to reach 99.3% of the supply voltage.

    HTH,
    --Rich
     
  10. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    Awsome RiJoRI!! I forgot half the stuff from tech school... I have figured most of it out but now I have one more question... In order to keep the circuit on and the relay energized until I shut the ignition off, can I keep the Discharge and Threshold pins disconnected?
     
  11. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    Okay guys, I am about 95% dones with my project... NOW, my problem is this... I don't know how to do the 5 second momentary pushbutton trigger still!! I tried to use an RC circuit but ended up that I need a low to trigger the circuit... How can I get a low out of an RC circuit to trigger? This is what I had... Don't laugh... I just started not too long ago and have NEVER designed anything... I want to start though so I thought this would be a good project... I just CANNOT get that darn timing down!!

    (Picture removed for revised version below)
     
  12. nanovate

    Distinguished Member

    May 7, 2007
    665
    1
    You can put an inverter circuit on the end of the RC circuit. Use an npn and pull-up resistor on the collector. The RC will be connected the base of the npn.When the RC charges above a certain level it will turn on the npn and the collector voltage will go low.
     
  13. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
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    Okay, I laid everything out on a test board and it worked 100% the way I wanted it to... As soon as I got it over to the circuit card and soldered everything, the circuit will come straight on as soon as you apply the 12V... I dunno what I am doing wrong as I am going over the schematic and looks to have everything hooked up correctly!! For some reason, the trigger is going low without me even touching the 5V signal... So my RC circuit is comming on without even doing anything!! Even if I discharge the cap, it still comes on right away... I will post up a revised schematic of what I am doing now... I will do it as it is on circuit board, not test board...
     
  14. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
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    Okay, here is the schematic... I guess I am just not seeing why the relay would switch on without the 5V RC circuit being triggered... However, the trigger is going low, but I just am not seeing why!? The 5V signal NEVER get tripped!! I have checked all connections for shorts and whatnot... Only thing I may think is wrong is that I had the trigger connected to the same power supply as the the VCC on the testboard causing the trig to be high until I charged the RC circuit to have it go to low...

    [​IMG]
     
  15. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,157
    When you hook the circuit into the car, what voltage are you going to be working with? 13.8 from the regulator?
     
  16. Neo1130

    Thread Starter Member

    Sep 3, 2007
    13
    0
    Yes, VCC is going to be 12V switched on by the ignition... Even when I am using my 6V test power supply you can barely hear it switch, but that is probably due to less current...
     
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