Author Topic: Cruise control not keeping set speed  (Read 14549 times)

ptashek

  • W116 Addict
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  • W116 owner
  • Location: Ireland
    • History of ZV9485
Re: Cruise control not keeping set speed
« Reply #60 on: 25 May 2020, 02:59 PM »
I've rebuilt the W124 amp today, it worked twice partially, then failed the same way again. Back to the drawing board with this one.

At least the speed signal is clean as a whistle now.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE (history, resto)

ptashek

  • W116 Addict
  • ****
  • Posts: 1,938
  • W116 owner
  • Location: Ireland
    • History of ZV9485
Re: Cruise control not keeping set speed
« Reply #61 on: 05 June 2020, 04:34 AM »
I've thrown the VDO junk amp in the proverbial bin, and decided to build my own. Because ain't nobody telling me I can't :)
If you don't hear from me in a few months, please check the nearest ditch...

Quote
The “thing”. An Arduino Nano Every as the brains, and a VNH7100BAS automotive-grade half-bridge controller, to manage the simulated actuator, which is made up of a micro 12V DC motor and a 10kΩ potentiometer. Plus a lonely NPN transistor to drive the simulated wheel, and a tiny hall sensor to simulate the instrument cluster speed feedback sensor. The half-bridge controller is capable of driving up-to 15 amps of continuous load at 28V max supply voltage, without need for active cooling. Thermally speaking, it won’t even notice the VDO actuator load (a measly 1.5 amps peak), so no derating curves to worry about etc.
1993 "Pearl Blue" W124 280TE
1988 "Arctic White" W124 200T
1979 "Icon Gold" W116 450SE (history, resto)