Past Projects
Ares I Upper Stage Propulsion System
Jeremiah Friend, President of Via Double E, LLC designed and developed a prototype pump motor inverter unit (PMIU) as part of NASA's Constellation program while working for Zin Technologies, Inc.
The PMIU is a 2kW, 6 switch, 400Hz, quasi-square wave inverter used to drive induction motors which circulate liquid hydrogen and liquid oxygen in the upper stage propulsion system.
Design work included a TI/Unitrode based DC/DC converter, loop stabilization in simulation, a 6-switch inverter, and gate drive generation using only discrete radiation hardened components.
Jeremiah Friend, President of Via Double E, LLC designed and developed a prototype pump motor inverter unit (PMIU) as part of NASA's Constellation program while working for Zin Technologies, Inc.
The PMIU is a 2kW, 6 switch, 400Hz, quasi-square wave inverter used to drive induction motors which circulate liquid hydrogen and liquid oxygen in the upper stage propulsion system.
Design work included a TI/Unitrode based DC/DC converter, loop stabilization in simulation, a 6-switch inverter, and gate drive generation using only discrete radiation hardened components.
Zero Boil-Off Tank Experiment (ZBOT)
As an engineer for Zin Technologies, Inc., Jeremiah Friend served as the lead electrical engineer for the zero boil-off tank experiment (ZBOT). ZBOT is a microgravity science glove-box experiment on-board the ISS and its research will aid the design of long-term storage systems for cryogenic fluids in space flight. The goal is to build cost effective and reliable cryogenic storage systems for both life support and propulsion systems by reducing mass and decreasing risks through enabling design concepts.
Design work included overall system architecture which allowed autonomous operation on board the ISS, while also maintaining the ability for the experiment to be commanded from the ground through satellite links and the ISS LAN. Circuits were designed for power conditioning, data acquisition, motor drives, and PID control for in-line fluid heaters.
As an engineer for Zin Technologies, Inc., Jeremiah Friend served as the lead electrical engineer for the zero boil-off tank experiment (ZBOT). ZBOT is a microgravity science glove-box experiment on-board the ISS and its research will aid the design of long-term storage systems for cryogenic fluids in space flight. The goal is to build cost effective and reliable cryogenic storage systems for both life support and propulsion systems by reducing mass and decreasing risks through enabling design concepts.
Design work included overall system architecture which allowed autonomous operation on board the ISS, while also maintaining the ability for the experiment to be commanded from the ground through satellite links and the ISS LAN. Circuits were designed for power conditioning, data acquisition, motor drives, and PID control for in-line fluid heaters.
32 Channel Data Acquisition Module
Configurable through RS232 or USB (via a PIC18F4550 microprocessor) for 4-wire RTD signal conditioning, this design achieves an accuracy of +/-0.02°C. This data acquisition board was designed to stack up with other commercial units in a PC/104 format and is also configurable for small signal analog voltage acquisition. The output can be configured for either raw counts or final engineering units.
Configurable through RS232 or USB (via a PIC18F4550 microprocessor) for 4-wire RTD signal conditioning, this design achieves an accuracy of +/-0.02°C. This data acquisition board was designed to stack up with other commercial units in a PC/104 format and is also configurable for small signal analog voltage acquisition. The output can be configured for either raw counts or final engineering units.
Solenoid Valve Driver
This unit was designed to minimize heating in solenoid valve coils for fluid valves being held in an active state for long periods of time. To reduce the power lost in a solenoid valve coil, a "hit and hold" technique can be employed which "hits" the solenoid valve at rated voltage for a short period of time, followed by dropping the applied voltage to a "hold" value which guarantees sufficient magnetic force to maintain the valve position. In this circuit, the hold time as well as the hit and hold voltage values are completely programmable in order to maintain ultimate flexibility.
This unit was designed to minimize heating in solenoid valve coils for fluid valves being held in an active state for long periods of time. To reduce the power lost in a solenoid valve coil, a "hit and hold" technique can be employed which "hits" the solenoid valve at rated voltage for a short period of time, followed by dropping the applied voltage to a "hold" value which guarantees sufficient magnetic force to maintain the valve position. In this circuit, the hold time as well as the hit and hold voltage values are completely programmable in order to maintain ultimate flexibility.
Custom Resistive Heater Driver
In a science experiment where resistive strip heaters and in-line fluid heaters were employed, the peak power applied to each load via a PID controller needed to be digitally adjustable by a master data acquisition and control unit. This custom heater driver allowed for precision control of the peak or maximum power applied to a number of loads, while maintaining PID control capabilities.
In a science experiment where resistive strip heaters and in-line fluid heaters were employed, the peak power applied to each load via a PID controller needed to be digitally adjustable by a master data acquisition and control unit. This custom heater driver allowed for precision control of the peak or maximum power applied to a number of loads, while maintaining PID control capabilities.
Custom Power Supply for High Power LED Light Engine
A custom power supply needed to be designed to drive a bank of high power LEDs (110W) from an AC power source (120V and 240V). In this project, the mechanical components were already mature so an AC topology was developed with no high frequency switching so that the design could fit into the volume available. In addition to maintaining a constant current through the LEDs during each input cycle, voltage feedback and thermal feedback were monitored in an analog circuit and used to fold power back for maximum LED protection. This circuit is UL approved.
A custom power supply needed to be designed to drive a bank of high power LEDs (110W) from an AC power source (120V and 240V). In this project, the mechanical components were already mature so an AC topology was developed with no high frequency switching so that the design could fit into the volume available. In addition to maintaining a constant current through the LEDs during each input cycle, voltage feedback and thermal feedback were monitored in an analog circuit and used to fold power back for maximum LED protection. This circuit is UL approved.
Control Electronics for Household Appliances
A PIC18F43K22 based design was developed to monitor signals from two sensors and control motorized ball valves, an LED display panel, and a high current relay for a GFCI outlet. The power supply section transformed 120Vac into low level DC voltages for the monitoring and control circuitry. A backup lithium ion battery pack was provided which is charged while AC power is present. Loss of AC input power automatically shifts the load to the lithium battery pack while the processor performs housekeeping functions and then enters a deep sleep mode. An analog conditioning circuit brings a signal representative of AC line voltage into an interrupt pin on the processor which causes it to wake up from deep sleep, perform start-up functions and resume normal operation. When AC power is restored, the load is automatically switched away from the battery and the charging circuit re-charges the lithium battery pack following standard chemistry specific algorithms in order to maximize battery life.
A PIC18F43K22 based design was developed to monitor signals from two sensors and control motorized ball valves, an LED display panel, and a high current relay for a GFCI outlet. The power supply section transformed 120Vac into low level DC voltages for the monitoring and control circuitry. A backup lithium ion battery pack was provided which is charged while AC power is present. Loss of AC input power automatically shifts the load to the lithium battery pack while the processor performs housekeeping functions and then enters a deep sleep mode. An analog conditioning circuit brings a signal representative of AC line voltage into an interrupt pin on the processor which causes it to wake up from deep sleep, perform start-up functions and resume normal operation. When AC power is restored, the load is automatically switched away from the battery and the charging circuit re-charges the lithium battery pack following standard chemistry specific algorithms in order to maximize battery life.
Additional Projects:
- WiFi enabled household water control valve
- Automated process control for high volume manufacturing
- IoT systems including multi-functional sensors used for motion detection, water flow detection, image acquisition, motion control and mapping, and liquid level sensing. Wireless technologies employed include MiWi, WiFi, Cellular, ZigBee, and LoRa.
- Smart sensors used for calibrating large weathering machines. Sensors include irradiance and temperature smart sensors which are calibrated using a PC application and then interface with the weathering machine for precise calibration of on board sensors.