Abstract: An air purifying respirator includes a dual stage fan that sucks outside air in through the filter canisters and then pushes the filtered air on to the user's mask or hood, where excess air escapes. A differential pressure sensor measures the pressure within the passages after the dual stage fan and in the ambient environment to estimate the user's rate of respiration. The microcontroller monitors the estimated rate of respiration, as well as the estimated altitude and its estimated amount of oxygen to calculate a user's filtered air flow need. The microcontroller adjusts the van via a fan controller to the appropriate air flow level. The microcontroller further monitors the battery level, filter life, and for low pressure within the user's mask and operates their respective indicators when problem levels arise. The battery supplies power to the microcontroller, power on/off button, and the dual stage fan.

Abstract: An air filtration system is described that is suited for CBRN and ColPro applications, and has an integrated inertial particle separator (IPS) and scavenge fan blower as a pre-dust/particle filter, a variable speed fan blower, and a filter housing that mounts two gas-particulate filter sets. The variable speed fan blower, managed by a motor control unit and motor speed algorithm, automatically adjusts its speed to maintain constant air flow regardless of its altitude.

Abstract: An air purifying respirator includes a dual stage fan that sucks outside air in through the filter canisters and then pushes the filtered air on to the user's mask or hood, where excess air escapes. A differential pressure sensor measures the pressure within the passages after the dual stage fan and in the ambient environment to estimate the user's rate of respiration. The microcontroller monitors the estimated rate of respiration, as well as the estimated altitude and its estimated amount of oxygen to calculate a user's filtered air flow need. The microcontroller adjusts the van via a fan controller to the appropriate air flow level. The microcontroller further monitors the battery level, filter life, and for low pressure within the user's mask and operates their respective indicators when problem levels arise. The battery supplies power to the microcontroller, power on/off button, and the dual stage fan.

Abstract: An air filtration system is described that is suited for CBRN and ColPro applications, and has an integrated inertial particle separator (IPS) and scavenge fan blower as a pre-dust/particle filter, a variable speed fan blower, and a filter housing that mounts two gas-particulate filter sets. The variable speed fan blower, managed by a motor control unit and motor speed algorithm, automatically adjusts its speed to maintain constant air flow regardless of its altitude.

Abstract: A multiple outflow valve control system for an aircraft is provided having a plurality of outflow valves that may be controlled independently via an all electrical control system. The outflow valves may be located in various locations in an aircraft. The control system may have a control loop controlling the outflow valve motors via open-loop PWM commands and may not have a motor speed feedback in the control loop. The cabin pressure control system may have manual and auto controls controlling separate motors on each outflow valve. Auto motor control may be performed via software biasing command logic included in the control laws in the control system. Air flow may be biased through selected outflow valves and the degree of biasing may be automatically or manually set.

Abstract: A multiple outflow valve control system for an aircraft is provided having a plurality of outflow valves that may be controlled independently via an all electrical control system. The outflow valves may be located in various locations in an aircraft. The control system may have a control loop controlling the outflow valve motors via open-loop PWM commands and may not have a motor speed feedback in the control loop. The cabin pressure control system may have manual and auto controls controlling separate motors on each outflow valve. Auto motor control may be performed via software biasing command logic included in the control laws in the control system. Air flow may be biased through selected outflow valves and the degree of biasing may be automatically or manually set.