ISRO Scientist/Engineer SC (Electronics) case studies
ISRO Scientist/Engineer SC (Electronics) · Put your knowledge to work in context.
The ISRO Scientist/Engineer SC (Electronics) recruitment exam is the written objective test used by ISRO's Centralised Recruitment Board to shortlist electronics engineers for the Scientist/Engineer 'SC' entry grade at ISRO centres such as VSSC, URSC, SAC and SDSC. It targets graduates in Electronics/Electronics and Communication engineering (or equivalent) who want a research-and-development career in space systems rather than a conventional industry role. The ISRO Scientist/Engineer SC (Electronics) case studies are 5 cases and about 4,337 words.
1High-Side MOSFET Switch: Thermal Margin After TID and SEGR Derating
A 28 V spacecraft payload uses a P-channel MOSFET as a high-side load switch. The load draws 3.0 A.
944 words, about 5 min2S-Band Telemetry Link: Predicted Margin Versus Measured Eb/N0
A 2.2 GHz S-band telemetry downlink from a 2500 km circular orbit carries 2.0 Mbit/s BPSK data. The transmitter delivers 4 W to the antenna; the transmit antenna gain is 3 dBi and the feed loss is 0.5 dB.
742 words, about 4 min3Reaction-Wheel Speed Loop Interacting With a Flexible Solar Array
A reaction-wheel speed loop on a GEO satellite controls a rigid hub with two flexible solar-array wings. The first bending mode is at 1.08 Hz with 0.5% damping; the wheel-speed loop crossover is 1.02 Hz.
871 words, about 4 min4MIL-STD-1553B Bus Loading and Fault-Detection Trade
A spacecraft avionics architecture uses a 1 Mbit/s MIL-STD-1553B bus with one bus controller and 40 remote terminals. The controller polls every terminal at 50 Hz.
828 words, about 4 min5Thermistor Thermal Channel: Resolution Versus Accuracy Budget
A spacecraft thermal channel uses a 10 kΩ NTC thermistor with β = 3500 K and R25 = 10 kΩ in a 5 V ratiometric divider with a 10 kΩ 0.1% reference resistor. The ADC is 12-bit, 0–5 V, with a 5.00 V reference and 1 mV RMS input noise.
952 words, about 5 min