Abstract: A battery charger which electronically discriminates between rechargeable and non-rechargeable batteries, and which charges only rechargeable NiCd batteries. This feature is made possible due to the variation in the internal resistances between various types of battery cells.

Abstract: A high current driver (100) for driving a high current load (110) in an electronic device powered by a battery (112) comprises a voltage reference (104) for generating a reference voltage, and a drive current controller (102, 302) responsive to a drive control signal for selectively switching the drive current controller (102, 302) from an active state for supplying current to the high current load (110), to an-inactive state for inhibiting the supply of current to the high current load (110). The drive current controller (102, 302) further controls the amount of current supplied to the high current load (110) when the battery (112) terminal voltage is substantially equal to the reference voltage. A load control element (108) is coupled to the drive current controller (102, 302) and drives the high current load (110) when the drive current controller (102, 302) is in the active state.

Abstract: A selective call receiver is provided that is capable of receiving a transmitted fragmented message and displaying the fragmented message in at least two scripts. The transmitted fragmented message includes a plurality of sequentially ordered message packets each comprising an address and message data, at least one of the message packets having a script select character within the message data. The fragmented message is received by a receiver and passed to a circuit for displaying the fragmented message in the scripts, such that a first portion of the fragmented message is displayed in one of the scripts and a second portion of the fragmented message subsequent to the script select character is displayed in another of the scripts. A retrieval circuit is capable of retrieving a garbled message fragment if a sequentially prior message fragment containing the script select character is missing from the fragmented message.

Abstract: A selective call receiver (105) for use in a selective call communication system (100) and a controller (206). The receiver (203) is for receiving and demodulating a digital signal which includes a predetermined sequence of A.times.N interleaved symbols representing a non-interleaved set of N tiers of symbols, each tier having A symbols, wherein A and N are positive integers. The controller (206) includes a deinterleaver (830) which reconstructs the non-interleaved set of N tiers of symbols from the demodulated signal, and a decoder (950) detects and corrects errors in the deinterleaved set of N tiers of symbols. The digital signal is transmitted simultaneously from two transmitters (103) having a difference frequency 1/P, and the symbols are transmitted at a rate of SPS symbols per second. The period of the difference frequency is given by P=(A.times.N)/SPS.

Abstract: An inertial acoustic pickup (300) for use with a string musical instrument (700) having a soundboard (702) for delivering acoustic energy, comprises a chassis (302) including a coil (304) coupled to the soundboard (702), an armature including upper and lower substantially parallel planar suspension members (310) having planar perimeter regions (308) coupled to the chassis (302), and comprising a plurality of independent planar circular non-linear spring members (312) arranged regularly about a central planar region (314) within the planar perimeter region (305), an inertial mass (316) suspended between the upper and lower planar suspension members (310) about the central planar region (314) and having an axis (342) extending therebetween and including a plurality of permanent magnets (320) arranged regularly about a perimeter of the inertial mass (316), whereby acoustic energy coupled to the chassis (302) from the soundboard (702) is transformed through the planar non-linear spring members (312) into motional

Abstract: A distributed data system utilizing a paging location system includes a plurality of local area networks (LAN) (38) that have a wireless data link associated therewith for accessing one of a plurality of personal data units (PDU) (10). Data transfer can be affected over a wireless link between antennas (18) and (44) by determining from an internal lookup table in each of the LANs (38) which of the LANs (38) is the homebase LAN (38). The data is then transferred to the homebase LAN (38) and the homebase LAN (38) then attempts to transfer the data to the destination PDU (10). If not located at that LAN (38), a paging message is then transferred through a paging system to all of the PDUs (10) and the destination PDU (10) then transmits a Ready-to-Receive message to the one of the LANs (38) that it is closest to. This is the receiving LAN (38) which then requests data to be transferred thereto from the homebase LAN (38) and then affects a transfer to the destination PDU (10).

Abstract: An taut armature, resonant impulse transducer (100) includes an armature (12), including an upper (14) and a lower (16) non-linear resonant suspension member, each including at least two juxtaposed planar compound beams (202, 204 and 206, 208) connected symmetrically about a contiguous planar central region (210), and further connected to two contiguous planar perimeter regions (212, 214), an electromagnetic driver (24, 26), coupled to the upper and lower non-linear resonant suspension members (14, 16) about the two contiguous planar perimeter regions (212, 214), the electromagnetic driver (24, 26) effecting an alternating electromagnetic field in response to an input signal, and a magnetic motional mass (18) suspended between the upper and lower non-linear resonant suspension members(14, 16) about the contiguous planar central region (210), and coupled to the alternating electromagnetic field for generating an alternating movement of the magnetic motional mass (18) in response thereto, the alternating moveme

Abstract: A dual mode transducer (600) includes an electromagnetic driver (604), an armature including upper and lower substantially parallel planar suspension members (610) coupled to the driver (604), and a magnetic motional mass (616) suspended between the suspension members (610). The suspension members (610) include a plurality of independent planar non-linear spring members (612) arranged regularly about the central region (614) within a perimeter region (608). The spring members (612) are defined by members having maximum opposing widths tapering to minimum opposing widths at midpoints thereon, the maximum opposing widths are coupled to the central region (614) and to the perimeter region (608). The motional mass (616) couples to the electromagnetic field which alternately moves the motional mass (616), the movement being transformed through the spring members (612) and the driver (604) into motional energy. A soundboard (1014), coupled to the driver (604), couples the motional energy to a user.

Abstract: A removable battery door clip has opposed pivoting stubs (176) for the door to be pivotally anchorable to a housing (20) and at least one projection (152) for the door to be snappably fastened with at least one retaining slot (234) of the housing.

Abstract: A method for battery saving in a selective call receiver (20) that comprises a baud rate detector (210) and a receiver circuit (202) for receiving and demodulating a selective call signal. The selective call signal comprises a preamble (102) and a plurality of data batches. Each of the plurality of data batches further comprises a synchronization codeword (104) and a plurality of assigned data frames (106). The method (30) begins when a predetermined baud rate is detected in each of the plurality of assigned data frames (106) in one of the plurality of data batches. Upon detecting the predetermined baud rate, the selective call receiver (20) inactivates the receiver circuit (202) for the duration of the synchronization codeword (104) in a subsequent one of the plurality of data batches. Otherwise, the receiver circuit (202) remains activated during the synchronization codeword (104) of the subsequent one of the plurality of data batches.

Abstract: A communication receiver (106) receives an address code word (1800) of a transmitted message, the message comprising the address code word (1800) and an associated data portion (1610), the address code word comprising an address portion (1802,1804). The communication receiver (106) corrects (2104) up to a predetermined number of bit errors in the received address code word (1800). The communication receiver (106) can conserve power following a failed correction of the address code word (1800). Alternatively, the communication receiver (106) compares (2108,2111) the address portion (1802,1804) of the corrected address code word (1800) to at least one predetermined subscription address (1704,1706). The communication receiver (106) can conserve power following a determination of no match (2110,2114,2308) between the address portion (1802,1804) of the corrected address code word (1800) and the at least one predetermined subscription address (1704,1706).

Abstract: An omnidirectional antenna (100) includes a resonator (102) and a ground plane (104).

Abstract: A resilient latch (70) and a method of attaching the latch to a pair of interlocked housings (50) having a recessed border and mating cavities (377) in the recessed border. Placed around the border of the paired housings, the latch having protrusions (727) engages with the cavities of the paired housings, as the latch is slid around the border.