Abstract: A vehicle detector comprising a flux gate magnetometer with vertical and horizontal sensing coils is positioned within a roadway. The ambient levels of the earth's magnetic field as sensed by the magnetometer are used to establish reference levels and deviations therefrom are evaluated by a microprocessor which produces a vehicle arrived signal when the vertical component of sensed perturbations exceed a threshold and in an alternate mode when either vertical or horizontal levels exceed threshold values. Both vertical and horizontal levels must fall below threshold levels to determine a departure in either mode. Vehicle arrival and departure events are encoded as NRZ data packets which are transmitted by an edge-fired antenna as FM modulated signals. A remote multi-channel receiver capable of responding to a plurality of magnetometer modulated FM transmitters processes the received data and provides signals that are used by traffic signal controlling computers.

Abstract: A paging encoder including a microcomputer having a look-up table containing code formats for the more popular paging systems and an energy conservation means whereby the microcomputer is maintained in an off state except when called upon to perform an encoding function by a keyboard input means. This is accomplished by a microcomputer programmed to contain a lookup table including tone and space data for a plurality of paging formats and routines for converting input data, such as a telephone number, to a tone and space code for a selected one of said paging formats as programmed by a selection means which alters the function of the microcomputer to cause it to provide the desired output tone and space codes in accordance with the selected paging format.