Medha Servo Drives Private Limited products

Electronic Governor is a maintenance free alternative to the mechanical Governors popularly used for this application. The Governor consists of a Control Unit mounted in the Driver cab, and an Actuator Unit mounted on the Engine. The Actuator Unit can be mounted exactly on the same Engine base as mechanical Governors. The Governor controls the engine speed, based on throttle handle position (popularly known as notch) selected by the Driver on the Driver Desk. Engine RPM is measured from a Tachogenerator or speed sensor mounted on the Engine. Digital PID control is used to calculate desired fuel rack position dynamically, based on the selected notch on throttle handle and measured Engine RPM. A Stepper motor drive is used in the Actuator Unit to control the fuel rack of Diesel Engine. 

Vigilance Control Device (VCD) is a microcontroller based safety device which will automatically apply penalty brakes in case the driver is incapacitated. Similar operation is available in older locomotives in the form of Deadman’s Lever.

CRDI system includes Engine Control Unit, Fuel Injectors, High Pressure Pumps and various Sensors. Pump driven by camshaft provides high pressure fuel to all injectors. This pressure level is controlled by ECU depending upon operating speed/power. Each injector has a solenoid valve to accurately control the fuel injection start and duration. ECU controls these parameters based on operating conditions like speed, power, load, Boost Air Pressure, Coolant Temperature etc. This continuous optimization based on various operating conditions is done to reduce fuel consumption and at the same time reduce emissions. In Mechanical fuel injection system, it is not possible to independently control injection start and duration for different operating speeds/powers.