1. A Familiarization to Speed Governor
Anil Chhikara
Motor Licensing Officer
Transport Department
GNCT, Delhi

2. CABLE MECHANISM TYPE FUEL MANAGEMENT TYPE
SPEED LIMITER
CABLE MECHANISM TYPE
FUEL MANAGEMENT TYPE

3. SPEED GOVERNOR Also called as SPEED LIMITER DEVICE(SLD)
ELECTRONIC SPEED GOVERNOR (ESG)
SPEED CONTROL DEVICE (SCD)

4. DEFINITION
Speed limiting device has primary function to control the fuel feed to the engine in order to limit the speed of the vehicle to a specified value without effecting the other performance parameter of the vehicle .

5. TYPES OF SPEED GOVERNOR
PRINCIPLE
PERFORMANCE
MECHANICAL
Welding of iron strip or bolt just below the accelerator pedal to restricts the engine rpm.
Lack of power
Pickup of vehicle falls drastically.
CABLE MECHANISM
Microcontroller receives the input signal from the speed sensor and send the signal out to the actuator
Actuator cuts the fuel & air intermittently and not let run the engine above prescribed speed.
FUEL MANAGEMENT
Management of calibrated fuel through ECU to control the vehicle speed.
Steady specified speed is achieved without any hiccups ensuring smooth ride.

6. MAIN COMPONENTS SPEED SENSOR ELECTRONIC CONTROL UNIT ACTUATORS
WIRING HARNESS

7. SPEED SENSOR HALL EFFECT TYPE – latest / reliable technology
REED SWITCH TYPE – redundant/non reliable technology
HALL EFFECT TYPE – latest / reliable technology

8. HALL EFFCT SENSOR Hall Effect Sensor Hall Effect Sensor
The Hall element is a small semiconductor plate when a current is pass through it in the presence of magnetic field generate voltage . This voltage is proportional to current and the magnetic field. This generation of voltage is called Hall effect.
Hall Effect Sensor
Hall Effect Sensor

9. ELECTRONIC CONTROL UNIT
This is an electronic circuit contains an array of resistance and capacitors with a 32 bit microcontroller, where all the input signal are analyzed and passing through the whole algorithms of software then a suitable out put is generated for final control elements called Actuator.

10. Actuators
The actuator is a translation of the converted controlled signal in to action .
It is an energy conversion device having an electrical input as signal and force and displacement as an output.
Mechanical
Electrical Solenoid

11. TEMPER PROOFNESS
Vehicle speed should not cross the set speed if any of the below condition occurred.
If sensor is bypassed
If ECU is bypassed
If wiring is bypassed
If complete system is bypassed

12. MECHANISM OF CABLE TYPE SPEED LIMITER

13. Regulation of speed of vehicles
Motor Vehicle Act , 1988 Sections 183,112,184,66
Central Motor Vehicle Rules, 1989 , Rule 118
Delhi Gazette Notification F. No PCO/STA/II/2001PF-2/194 Dated 24 February 2003 & subsequent guidelines dated
SLD Standards AIS 018, IS :10250, IS : 9000

14. REGULATION /ENFORCEMENT ON ROADS
In no case transport vehicle should run above 40 kmph in Delhi roads.
ESG should not be tempered .
Seals of ESG should be intact.
ESG should not be removed .
Annual Maintenance Contract /History card should be kept along the vehicle documents.

15. MAINTENANCE OF ESG
Quarterly calibration and maintenance services are mandatory.
No road side mechanic /unauthorized technicians are allowed to repair the ESG.
In case ESG defective the vehicle is not allowed to ply on hire – reward purpose.
The operator / driver may get repairs/correction from authorized dealer workshops.

16. Sealing locations ECU Engine Location inside driver cabin
Electronic sensor cable
ECU
Accelerator Pedal
Accelerator linkages
Actuator Motor
Engine
Gear Box
Speed sensor
Location Inside cabin or under chasses.

17. Electronic By-passing with intact seals
By pass switch
Location inside driver cabin
Electronic sensor cable
ECU
Accelerator Pedal
Accelerator linkages
Actuator Motor
Engine
Gear Box
Speed sensor
Location Inside cabin or under chasses.

18. Tempering of the SLD
Main seals are located at the sub - assemblies i.e. speed sensor, ECU & Actuator Motor
The other seals are fixed at accelerator linkages depending upon model of ESG & vehicle which can be additional one or two.
The possibility of electronic tempering may not be ruled out even the seals are intact, if the insulation of the sensor pulse wire is sheared off and the earthed with the help of shunt (additional piece of wire) and with the help of a switch located at convenient reach of driver.
The driver can by-pass the speed governor and the vehicle speed can shoot up to his desire.
In case some other tempering is carried out the chances of SLD at working mode will not be possible and will damage the electronic components.

19. At gear box / speed sensor
SEAL LOCATIONS - a
At gear box / speed sensor

20. SEAL LOCATION -b
At ECU

21. SEAL LOCATION- c
At throttle / linkages

22. THANKING YOU