Abstract: A control system and method for the seat suspension described herein utilizes a pneumatic cylinder which forms the shock absorber, an air compressor, solenoid valve and a microelectromechanical system (MEMS) based control. In operation, the pneumatic cylinder is filled with a compressible gas and sustained under pressure for the purpose of supporting the static weight of the occupant as well as providing comfort by reducing transmitted vibrations and high acceleration from external disturbances. A control process utilizes vibration data from the MEMS to adjust the gas cylinder pressure accordingly to reduce and damp the undulations of the supported mass.

Abstract: A control system and method for the seat suspension described herein utilizes a pneumatic cylinder which forms the shock absorber, an air compressor, solenoid valve and a microelectromechanical system (MEMS) based control. In operation, the pneumatic cylinder is filled with a compressible gas and sustained under pressure for the purpose of supporting the static weight of the occupant as well as providing comfort by reducing transmitted vibrations and high acceleration from external disturbances. A control process utilizes vibration data from the MEMS to adjust the gas cylinder pressure accordingly to reduce and damp the undulations of the supported mass.

Abstract: The invention provides a circuit to protect an AC motor powered by a Variable Frequency Drive (VFD) from overvoltages caused by reflected waves. A full wave bridge rectifier circuit across the lines of the motor to be protected provides rectified voltage output to a capacitor, across which a low resistance discharge resistor in series with one or more zener diodes is attached. When an overvoltage above the clamping voltage of the zener diode(s) occurs across the protected lines, the zener diode(s) will conduct, causing the excess charge across the capacitor to discharge through the resistor until the voltage drops below the clamping voltage of the diode(s).