Silcom Research Limited

J Peter Williams

Gyles Panther

Donald W Campbell

The present invention relates to a radio receiver for receiving a radio signal, a first circuit for beating the signal to zero intermediate frequency in phase and quadrature shifted signals, a circuit for amplifying the in phase and quadrature shifted zero intermediate frequency signals, a second circuit for beating the amplified intermediate frequency signals to predetermined non-zero intermediate frequency in phase and quadrature shifted signals, a summer for summing the non-zero signals, and a circuit for applying the summed signals to a discriminator to obtain an output signal. Other embodiments are extended POCSAG for enhanced battery saving, paging sequence numbers for reception integrity control, digital AFC, script control of the pager for organizer/schedule applications, a vibrator holster for improved pager format and saving of battery power, intelligent low battery detection, and features arising from electronic on/off function.

Radio page receiver with automatic cyclical turn on

A low battery condition is determined by sampling battery terminal voltage with a voltage comparator under light and heavy loading, and indicating a low battery condition when the rate of change of the sampled voltage or the rate of change of the internal resistance of the battery is greater than a predetermined limit.

Intelligent low battery detection circuit for a paging receiver

A holster for a radio pager contains an electrical element which can be detected by the matching radio pager when the pager is inserted into the holster. In one embodiment the pager and holster have matching electrical contacts which are made when the pager is inserted into the holster. The pager contains means to sense the connection of a specific impedance and to convey this data to an internal control device. The control device has the capability to alter the mode of alert from vibrate to an alternate alert mode such as audible alert, according to the pre-selected choice of the user, under control of the low impedance sense signal. The holster sense circuit output is also used by the control device to invert the orientation of displayed information, to provide for on-belt reading of a front faced display pager.

Pager with automatic detection of insertion into holster

A holster assembly for retaining a radio pager or data receiver including a clip fixed to the assembly having a first position for resiliently clamping the holster assembly to an article of clothing and another stable open position for supporting the assembly on a surface as a stand for the pager or receiver, a vibrator alert apparatus and a battery connected thereto contained wholly within a housing formed by the holster assembly.

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Munster, Canada

J Peter Williams