Feed Positioning System
Specifications of feed positioning system
- Accuracy of feed positioning system = 2 arc min. from the dish vertex
- Resolution = 1 arc min.
- Drive specifications :
- Half Hp DC servo motor
- Speed : 2000 RPM
- Torque : 2.7 N-m
- Operating Voltage : 55 Volts
- Weight : 11kg
- Inertia : 2.2 kg sqm X 10 ˆ (-3)
- Thermal time constant: 23 min.
- Electrical time constant : 2 milliseconds
- Mechanical Time constant : 14.7 millisec.
- Torque constant : 0.24 N-m/A
- Inductance : 1.1 mH
- Armature Resistance : 0.62 ohm
- Peak current : 100 amp.
- Voltage constant : 25V per 1000 rpm
- Half Hp DC servo motor
- Tachometer :
- 4V/1000 rpm
- Ripple : 1.5% at 400 rpm
- Inertia : 8.4 X 10 ˆ (-5) kg-sqm
- Weight : 0.32 Kg
- Holding torque : 13 N-m
- Rated voltage to be applied for releasing brakes :24 VDC
- Coil current : 1 Amp
- Encoder : Incremental encoder with one arc min. resolution
- Speed profile : Trapezoidal
- Speed control : PWM technique at 10 KHz.
- Power drive : 'H' Configuration using IRF150 MOSFETS.
- PWM Generation : 8051FA microcontroller with non volatile memory to retain current position and enabling Liquid crystal display. Microcontroller communicates with Antenna Base Computer using RS-485 protocol with an asynchronous link.