PPT Development for Nanosatellite Applications: Experimental Results
In this paper, the design and performances of a pulsed plasma thruster (PPT) for nanosatellite applications will be presented. The breadboard model PPT presented in this paper will be a part of six PPTs propulsion system designed to provide attitude and translational control for a 20-kg nanosatellite for a total delta-V of 40 m/s. The thruster performances have been characterized in terms of electrical parameters, mass bit, impulse bit, and specific impulse. The thruster was found to be compliant with the mission requirement. Moreover, preliminary electromagnetic noise interference measurements have been performed. The spark plug discharge was found to be the main source of noise as already found by previous authors. From the collected data, it can be inferred that the noise is mostly radiated.
A single-switch high voltage quasi-resonant DC-DC converter for a pulsed plasma thruster
In nano-satellites, the pulsed plasma thruster (PPT) is a suitable electronic propulsion system for drag compensation or attitude control. In this paper, a new quasi-resonant converter topology is proposed for the PPT igniter. It consists of a resonant tank, a step-up transformer and a Cockcroft-Walton voltage multiplier circuit. As compared to other resonant converters, the proposed topology uses a single switch. This improves the reliability and eases switching control. The resonant tank is driven to work at quasi-resonant state to obtain zero-current-switching (ZCS). This reduces switching noise and voltage spike. A prototype circuit has been developed to validate the concept. The output voltage is set to 4kV from a 5V power supply, and the preliminary experimental results show that the circuit works as analyzed.
Fully Integrated Bidirectional CMOS-MEMS Flow Sensor With Low Power Pulse Operation
Leveraging More-than-Moore technology, we demonstrate an integrated CMOS MEMS flow sensor via a very compact system on chip (SoC) that can sense the bidirectional N2 gas flow. Our SoC features a very low-noise instrumentation amplifier that is implemented on a CMOS wafer and serves as a readout integrated circuit for a thermoresistive micro-calorimetric flow sensor which is fabricated on a MEMS wafer. A compact heterogeneous integration is achieved by combining the two wafers via the proprietary InvenSense AlN process. The measured sensitivity of our CMOS MEMS flow sensor is 98 mV/sccm which is three times better than the state-of-the-art counterpart. The flow range measured by our SoC is from −26 to 26 m/s (from −50 to 50 sccm). Moreover, the pulsed heater operation makes this proposed SoC flow sensor a very low power (<9 mW) and, thus, a promising candidate for the Internet-of-Things applications in smart home/green buildings.