[Vwdiesel] Re: Glow plug monitoring: Miser's makeover

[Mark Shepherd]

  ----- Original Message ----- 
  From: Mark Shepherd 
  To: vwdiesel at vwfans.com 
  Sent: Wednesday, December 22, 2004 10:49 AM
  Subject: Glow plug monitoring: Miser's makeover


  Always talking in a riddle; 
  With the Miser in the middle
  Makes for many thoughts a muddle
  Time to clear up all the fuddle...

  I committed my cardinal sin of changing my own thread whilst still leaving remnants of my previous/parallel one... (the diagram attempt)

  1st my new thread:
  My new switch that cuts off the glow plugs early/allows recycling is in series with the energising coil of the relay.  It is actually located indpendantly from the main fuse board [ PO gasser conversion] (which may or may not restrict access to this 'supply line') 
  My supply line is basically coming from the ignition switch. There are no other controls to
  the relay ( hotwater/alt/door etc) It always glows for approx 45 seconds. 
  With the switch I can turn them off early  or reactivate the timer or leave off for imobiliser mode.

  Back to the GP monitoring...
  My response was a solution (attempt) to fulfill the 'client' request for a display of 4 LEDs onto a switch blank. 
  I had forgotten the ball park 2 Volts needed for full LED operation...
   (some glow at what voltage?)
  This system would probably need to have an OP Amp switched or 4 OP AMPs.

  Mike dug out a better sol'n from me which is to simply use  4 ballasted LEDs each 
  earthed'  through a GP. 
  Individualising the power supplies to the GPs with a Skottkey diode rated at 20 A with a
  Voltage drop of only 0.25 Volts and a power loss of only 5 watts would isolate each circuit.
  This voltage drop may also improve longevity (a lot of plugs say 11 volts on them)

  Radio Spares sell these for £5 for 5 to us here in Limeyland so they'll be about 50 cents to you guys

  Miserly...but not invisible :op