Why………….?

coz Speed thrills but Kills!

Why Should Speed Governor / Limiter be Installed

SPEED LIMITATION DEVICE

Speed Limitation Device (SLD), commonly known as Vehicle Speed Governor is a micro-controller based electronic unit, which constantly monitors the speed of a vehicle and governs the speed within the set limit. The Unit offers a variety of benefits to the fleet owners, drivers and passengers. The advantages of the Speed Limitation Device include :

Better safety by avoiding over-speeding Reduced strain on engines, thereby increasing the life of engines Increased Fuel Economy Improved Operational Efficiency Negligible Current Consumption (10 MA in Sleep Mode) Easy Installation

Speed Limitation Device comprises of

Electronic Control Unit : The Electronic Control Unit is the brain of the system that receives the signals from the speed sensor and activates the control module to govern the speed of the vehicle. The Set Speed, Speedometer Ratio and Gearbox rpm are fed into the ECU with the help of a Hand Held Programmer.

Speed Sensor : A specially designed two pulse Hall Effect Sensor is used to generate pulses in relation to the speed of the vehicle and transmit the same to the Electronic Control Unit. The sensor is easily mountable on the gear- box without loss or modification to any existing part. The mechanism has been designed to withstand hazardous and dusty, corrosive and grimy environment and ensure efficiency and reliability for a long time.

Solenoid Valve :

The solenoid valve is a 2 way valve which controls the flow of fluid through a single passage. It has two ports, an inlet and outlet. A normally closed valve does not pass fuel unless it is energized. There is fail-safe positive valve closing in the event of power disconnection that prevents flooding and overfilling. The long life aluminum casting and waterproof coils insure performance consistency for a long life. Minimum pressure drop and internal design of this valve assures exceptional flow performances.

The Electronic Control Unit is powered from the battery through the Ignition switch. When ignition is turned ON, the ECU is powered. The ECU activates the solenoid valve, which opens allowing the fuel to be injected in to the engine. The electronically controlled, solenoid flow valve regulates fuel and the system offers speed control in all climatic conditions for diesel vehicles.

When the vehicle is in motion, the Electronic Control Unit receives frequency signals from the speed sensor mounted on the engine gearbox. At a preset frequency programmed by the computer, the ECU transmits a signal to the fuel flow solenoid valve. The valve closes reducing the fuel supply, which in turn reduces the vehicle speed.

The Electronic control unit virtually eliminates all moving parts and there is no throttle delay and the fast reaction time of the solenoid valve makes it one of the most efficient speed limiters.

Principle of Operation

Stabilized Speed:Speed shall not vary by more than 4 % of the Stabilized speed (or) 2 Km/hr whichever is higher. The rate of change of speed shall not exceed 0.2 m/sec2 when measured on a period greater than 0.1 seconds.

The Speed Limitation Device is designed as per Automotive Industry Standards AIS-018/2001/July 2001 (IS 10250)

Tamper ProofTamper Proofing is achieved by not allowing acceleration beyond the ‘set’ speed in the following conditions:

If Power or Signal wires to the ECU are sealed for total security.If ECU Module is bypassed in the event of tampering with a time pulse relay with a set frequency in order to maintain a controlled fuel flow to the solenoid valve.If Speed Sensor is so positioned that it is not easily reachable.

Specifications

Sl No Item Specification Remarks

1 Rated Voltage 12 V24 V DC -

2 Rated Electric Current

1.0 Amp or Less

-

3 Operating Temperature

-20°C ~ + 80°C

Water Proof

4 Weight (Net) 840 gram / Unit

-

5 Dimension (package) 130x 110x130 -

How Does The Limiter Function

E C USolenoidValve

Fuel injection pump

FuelFilter

DieselTank

sensorDiesel pipe line

Electric power

Speed signal

SCHEMATIC SHOWING PROCESS DIAGRAM FOR SPEED CONTROL

Technical Specifications

Electronic Control Unit Operating Voltage : 12 V – 32 V DCOperating Temperature : 10º C to 55º C ± 2º COperating Current : 150 mA max.

Solenoid ValveOperating Voltage : 12 V DCOperating Current : 500 mA ± 2%Diameter : 4 - 7 mmDifferential pressure : 0 – 2.2 Mpa.

Speed SensorOperating Voltage : 10 V – 14 VOperating Frequency : 1 Hz to 400 HzNo. of Pulses : 2 Pulses / rotationDuty Cycle Signal : 100 % of Total Time PeriodOutput Signal Amplitude : 4 V to 2.7 V

HOVEL’S SPEED LIMITER SYSTEM SYSTEM