Thread: t vago's MPGuino workspace thread
View Single Post
Old 09-05-2014, 08:26 AM   #393 (permalink)
AndrzejM
Master EcoModder
 
AndrzejM's Avatar
 
Join Date: Oct 2011
Location: Poland
Posts: 840

Berta - '97 BMW 318 tds Compact
90 day: 62.03 mpg (US)

Charlie - '07 Citroen C4 Grand Picasso Exclusive
90 day: 37.58 mpg (US)

Corsa - '05 Opel Corsa C
90 day: 53.22 mpg (US)

Mruczek - '03 Audi A2
90 day: 60.61 mpg (US)
Thanks: 185
Thanked 167 Times in 117 Posts
Quote:
Originally Posted by tvcsantos View Post
shed some light and tell me why do wee need to connect a 50k resistor to the vss followed by the 5.1V zener diode....

Thanks,
Tiago
Tiago,

VSS sensor is connected to ECU (in most cases) and to a speedometer, we don't want to alter these readings that's why 50k resistor comes in handy cutting the current it's second role is to secure Zener diode of excesive current. And the diode itself is to cut all the signals that are comming from VSS to Arduino's logics level (5V).

HTH
__________________


Quote:
Gerhard Plattner: "The best attitude is to consider fuel saving a kind of sport. Everybody who has enough money for a strong car, can drive fast and hit the pedal. But saving fuel requires concentration, self-control and cleverness. It's a challenge with the nice effect of saving you money that you can use for other more important things."
  Reply With Quote
The Following User Says Thank You to AndrzejM For This Useful Post:
t vago (09-05-2014)