Abstract:
A voice privacy adapter inverts the order of frequencies in a band of frequencies transmitted by radio to prevent unauthorized reception. The adapter includes an input circuit for selecting signals from one of either a transmitter or receiver in a two-way radio. A balanced modulator-chopper heterodynes the modulation signal with signals from a bistable multivibrator which is driven by an oscillator to produce a double sideband, suppressed carrier signal. The upper sideband is attenuated and the lower sideband is coupled to either the transmitter or receiver. The inversion of the signal at the transmitter followed by a second inversion at the receiver restores the modulation signal. Use of the balanced modulator-chopper eliminates all of the frequency components of the modulation signal thereby insuring privacy. The balanced modulator-chopper may be easily disabled allowing use of the radio without frequency inversion.
Abstract:
Digital information to be decoded is transmitted over a voice band transmission medium as a sequence of half-cycles of tone of different frequencies, with different frequency tones being utilized for mark and space data bits. Only a half-cycle is required for each data bit with a phase reversal occurring at each data bit. The incoming signals are transformed into a sequence of zero crossings with the pulse interval time duration between these zero crossings being compared with a local frequency standard. At the end of each pulse interval, the decision of whether or not a mark or space has been received is determined in accordance with the count stored in a counter driven by the local frequency standard. The counter then is reset, storing a new count during the next half-cycle signal received.
Abstract:
A shock isolator (30) is provided within the housing (38) of a selective call receiver to substantially increase the natural frequency of vibration of the housing (38) and the printed circuit boards (54, 56) within the housing. The shock isolator (30) is a body of elastomeric material, preferably butyl rubber, which has component receiving apertures (32) molded therein for receiving the components (46, 48, 50) on the printed circuit board while at the same time contacting the printed circuit board. Th? ??yl rubber has a damping of at least 25 % (preferably 50 %) and a Durometer of between 50 and 70 type A (prererably 60).
Abstract:
Un dispositivo electronico portatil (100) comprende un dispositivo anexo (190, 195), un vibrador (175), y un procesador (105) acoplado entre el dispositivo anexo (190, 195) y el vibrador (175); el procesador (105) esta adaptado para detectar el dispositivo anexo (190, 195), determinar una identificacion para el dispositivo anexo (190, 195), asociar un voltaje de accionamiento con la identificacion, y accionar el vibrador (175) utilizando el voltaje de accionamiento.
Abstract:
A system (100) for communicating multimedia messages includes a multimedia message server (102) that is operable to transmit (1404, 1406, 1408) visual media, a vibration melody (1200), and an audio segment (1300) that is preferably filtered (1402) to exclude frequencies of the vibration melody (1200) through a network (104) to a client device (106), and is operable to, preferably at a later time, to transmit instructions (1410) to the client device (106) to output the vibration melody (1200), audio segment (1300) and visual media. At the client device, (106) the audio segment (1300) and the vibration melody (1200) and visual media are preferably stored (1504, 1508, 1512) in a memory (608) and in response to the instruction signal are read (1616, 1518, 1520) from the memory (608), decoded (1522, 1524, 1526) and output (1528, 1530, 1532) to a user. The vibration melody (1200) and the audio segment (1300) are preferably applied at least partially concurrently applied to an electromechanical transducer (212).
Abstract:
A system (100) for communicating multimedia messages includes a multimedia message server (102) that is operable to transmit (1404, 1406, 1408) visual media, a vibration melody (1200), and an audio segment (1300) that is preferably filtered (1402) to exclude frequencies of the vibration melody (1200) through a network (104) to a client device (106), and is operable to, preferably at a later time, to transmit instructions (1410) to the client device (106) to output the vibration melody (1200), audio segment (1300) and visual media. At the client device, (106) the audio segment (1300) and the vibration melody (1200) and visual media are preferably stored (1504, 1508, 1512) in a memory (608) and in response to the instruction signal are read (1616, 1518, 1520) from the memory (608), decoded (1522, 1524, 1526) and output (1528, 1530, 1532) to a user. The vibration melody (1200) and the audio segment (1300) are preferably applied at least partially concurrently applied to an electromechanical transducer (212).
Abstract:
A portable electronic device (100) comprises an attached device (190,195), a vibrator (175), and a processor (105) coupled between the attached device (190, 195) and the vibrator (175). The processor (105) is adapted to detect the attached device (190, 195), determine an identification for the attached device (190,195), associate a drive voltage with the identification, and drive the vibrator (175) using the drive voltage.