Abstract: Ultrasonic transducing elements (11, 12) are used to measure vibrations of a nearby musical drumhead or other vibrating surface (13). A first ultrasonic transducer (11) emits an ultrasonic signal (14) and a second ultrasonic transducer (12) listens for an echo of that signal (14). A phase change of the echoed (reflected) signal (202) is compared to a reference signal (206) to create a representation signal (216) which represents the movement of the drumhead or other vibrating surface (13). For this comparison to be properly made, a deviation signal (220) is generated that defines an average deviation of the reference signal (206) from optimum, which is then used to self-align the referee signal (206) to the reflected signal (202).

Abstract: A moble radio system is disclosed in which communication is established between at least two user-operable stations over one of a plurality of channels by operating the user-operable stations in accordance with the following steps:(1) When in the receive mode (the push-to-talk switch is open):(i) incrementing the channel selector to select a channel;(ii) determining if a carrier signal is present on the selected channel:(iii) if a carrier signal is not present, returning to step (1) (i);(iv) if a carrier signal is present, determining if the selected trunk identification signal is present on the carrier signal;(v) if the selected trunk identification signal is not present, returning to step (1) (i); and(vi) if the selected trunk identification signal is present on the carrier signal, enabling said transmitter for push-to-talk operation.

Abstract: An elastomeric connector for permanently or temporarily (for testing purposes) connecting area array chips without solder balls or wire bonds comprising an elastomer base material having through-hole conductors deposited therein, and surface conductor tabs which are electrically connected to the through-hole conductors deposited thereon. The surface conductor tabs have an overhanging contact region extending past the periphery of the through-hole conductors. Upon contact between the input/output pads of a chip and the overhanging contact regions of the elastomeric connector when aligned and biased towards each other, a requisite pressure causes a reactionary force by the elastomer base which facilites contact and automatic wipe. The elastomeric connectors may replace solder balls in chip connection applications, or may replace buckling beam test probe heads in chip test applications.