fuel valve control system is to control the fuel valve in the vehicles (when the fuel is open the led is LOW and when the fuel valve is closed the led is HIGH

 

all you need is:

  1. Arduino uno
  2. opoto coupler
  3. rectifier diode
  4. RELAY ( IC )
  5.  Red led
  6. push button
  7. 100k resistance
  8. 10k resistance

 

how it works : 

when the fuel valve is open Relay is high  and the led is low and when press push button the relay is low (Cut off power from the fuel valve ) and the led is High