Abstract: This device has a detection means to measure the relative amount of air movement in its vicinity. The detection means is coupled to a processing means for creating a variable trigger signal that is proportional to detected air movement. The detection means consists of a differential pressure transducer mounted inside a specially-shaped enclosure. The pressure transducer is arranged to measure the air pressure difference between two holes in the enclosure. The shape of the enclosure causes air to flow at different velocities near the holes, creating a differential air pressure. The processing means consists of a microprocessor that periodically samples the signal from the differential pressure transducer. A programmed algorithm calculates a variable trigger signal value based on a plurality of sampled signals. The processing means can also incorporate an algorithm for digitally generating audio signals that have attributes based on the value of the trigger signal.

Abstract: This device has a detection means to measure the relative amount of air movement in its vicinity. The detection means is coupled to a processing means for creating a variable trigger signal that is proportional to detected air movement. The detection means consists of a differential pressure transducer mounted inside a specially-shaped enclosure. The pressure transducer is arranged to measure the air pressure difference between two holes in the enclosure. The shape of the enclosure causes air to flow at different velocities near the holes, creating a differential air pressure. The processing means consists of a microprocessor that periodically samples the signal from the differential pressure transducer. A programmed algorithm calculates a variable trigger signal value based on a plurality of sampled signals. The processing means can also incorporate an algorithm for digitally generating audio signals that have attributes based on the value of the trigger signal.

Abstract: This device can record descent data for successive skydiving jumps with a pressure transducer for providing a pressure signal signifying ambient pressure. The device also has a processor coupled to the pressure transducer for displaying descent data on a display. The processor has a triggering routine and a recording routine. The triggering routine can provide a trigger signal in response to predetermined changes in the pressure signal from the pressure transducer. The recording routine can record for each jump in response to the trigger signal, a datum corresponding to the pressure signal. Each datum is held for at least a predetermined number of succeeding jumps. A temperature sensor coupled to the processor can provide a temperature signal signifying ambient temperature. The processor can display through the display, altitude signals derived from the pressure signal and adjusted by the temperature signal.