Abstract: This RF connector includes a strip line for providing a proper impedance match to coaxial cable. At one end of the strip line, pins are attached to a center conductor and to the ground plane to mate with flush coaxial contacts. In a modified version, the ground connection is provided by a flexible member that is attached to the strip line and has a ground contact projecting therefrom. The flexible member provides biasing force on the ground contact. A resilient pad engages the strip line to urge the contacts into engagement.

Abstract: An electrical connector having a plurality of contacts located within a housing. A multiple conductor electrical cable is received in another portion of the housing and the contacts and conductors are electrically connected. A flex circuit, which forms the contacts, is used for the electrical connection for the conductors. The flex circuit has one end wrapped around a cylindrical resilient member to form the contacts. The flex circuit is received by a support member in the housing for providing additional resilient support to the contacts.

Abstract: A detachable mounting clip arrangement according to the present invention includes a mounting clip supported by a support structure. The mounting clip is coupled to the support structure in a manner which allows rotation of the mounting clip between a first or normal position and a second position. A latching mechanism is coupled to the support structure so that when the mounting clip is in the first or normal position the latch is closed and the mounting clip is rotated to the second position, the latch opens. This is accomplished by a CAM pin coupled to the mounting clip which engages a CAM follower slot in a sliding latch member. When the mounting clip is rotated the sliding latch member slides with respect to a fixed latch member thereby opening the latch.

Abstract: A DC to DC converter includes a power input for receiving power at a predetermined input voltage. The converter is current-controlled to provide output power at a predetermined output voltage and several output current levels. The converter is further selectively controlled for either continuous or intermittent mode of operation. The continuous mode provides the higher output current levels and the intermittent mode provides the lowest output current level.

Abstract: A frequency synthesized transceiver capable of tuning to a plurality of communication channels is disclosed. The transceiver includes a receiver and a transmitter section which are coupled to the synthesizer which generates the appropriate injection signals to achieve tuning. A battery saving circuit generates a battery saving signal having a predetermined duty cycle and period and is responsive to the phase detector in the synthesizer to disrupt power to the synthesizer while maintaining precise tuning. The battery saver circuit is also responsive to the transceiver. In a normal receive operation, a battery saving circuit synchronizes its battery saving signal with the hold condition of the phase detector to disrupt power to selected modules in the synthesizer without altering the injection frequency of the receiver. In a standby mode, power is disrupted to all modules in the receiver, the selected modules in the phase locked loop and the voltage controlled oscillator.

Abstract: A backlighted display system includes a liquid crystal display, a flat light guide behind the display, and light emitting diodes (LED's). The light guide is a molded slab of clear polycarbonate material with two planes depressed into its rear surface. Four segmented bordering surfaces are approximately arcuate in shape. The depressed planes, the segmented bordering surfaces, and the rear surface are coated with a reflective white paint. LED holders are integrally molded with the light guide. A central portion of the front surface is optionally textured. The display system provides thin construction with even light distribution across the width of the display, low power consumption, and good outdoor visibility at dusk or dawn.

Abstract: An interface circuit is coupled between the last stage of an FSK receiver and a limiter to provide a biasing voltage signal to the limiter. The receiver includes a power saver circuit which supplies power on an interrupted basis. The interface circuit contains maximum and minimum detectors which derive and hold voltages corresponding to the maximum and minimum values of the discriminated signal from the receiver. These maximum and minimum corresponding voltages are averaged in a predetermined manner to provide the biasing voltage to the limiter. Thus, a proper bias voltage level can be accurately and quickly determined, and supplied to the limiter when power is supplied.

Abstract: A sampled input signal is quantized to lie within a predetermined magnitude range. The quantized input signal is coupled to a bandpass filter which selects the digital signal to be processed. The bandlimited signal is then coupled to a feedback automatic gain control circuit which removes the slow variations in the envelope of the input signal. The output of the feedback AGC circuit is then coupled to a feedforward AGC circuit which removes the fast variations in the envelope of the input signal. The feedback AGC and the feed forward AGC circuits share a common envelope detector, that is composed of a squaring operation and low pass filter operation. The feedback AGC circuit also reduces the dynamic range of the input signal which is required of the feed forward AGC circuit. The processed signal is then demodulated with a quadrature FM detector. The output of the FM detector may be low pass filtered, and coupled to a D/A converter to produce an audio message signal.

Abstract: An alarm system for sensing an alarm condition within a relevant alarm area includes one or more portable alarm units for sensing an alarm condition. Each alarm unit includes a radio frequency transmitter for identifying the alarm unit and a secondary, audio, transmitter for defining the relevant alarm area. The system also includes a plurality of transponders. Each transponder includes a primary receiver for receiving a radio message from an alarm unit and a secondary receiver for receiving an audio signal from the alarm unit. A real-time clock in each transponder provides the elapsed time between receipt of a primary and receipt of the secondary alarm signals. The alerted transponders then transmit to a control unit a transponder address code, an alarm unit identification code and an elapsed time indicia. Based on the address code or codes and the minimal elapsed times detected by the control unit, the relevant alarm area can be determined.

Abstract: A low profile antenna comprised of a driven element and a parasitic element spaced above a ground plane. The driven element is connected at one end to the feedpoint of the radio device to which it is attached, the opposite end thereof being free. The parasitic element is connected to the ground plane by its end nearest the feedpoint, the opposite end thereof being free. In the preferred embodiment the parasitic element length and the driven element length are both approximately equal to a quarter wavelength at the operating frequency.

Abstract: An inductorless quadrature demodulator for frequency modulated signals is disclosed. A limited FM signal is passed through an active filter (26) and a phase shift network (30) to produce a quadrature signal. The limited FM signal is compared with the quadrature signal in an EXCLUSIVE OR gate (24) and then low pass filtered (36) to obtain recovered audio. The active filter (26) includes a transconductance amplifier (60) whose center frequency can be adjusted by appropriate adjustment of the amplifier's bias current. The bias current is temperature compensated to allow operation of the demodulator over a wide temperature range.

Abstract: An interconnection mask which is sandwiched between two members to be bonded together is comprised of a thin sheet of preselected material which has a plurality of apertures therein which are positioned, sized, and shaped to define the common bonding areas between the two members whereby structural failures induced by bonding and loading characteristics of the two members are minimized.

Abstract: Apparatus for discharging accumulated electrostatic charge from the human body includes a conductive ring to be worn on a finger. A first connector is attached to and electrically connected to the conductive ring. A cable with a mating connector plugs into the first connector. A second connector at the other end of the cable is connected to ground. A series resistor, located in the mating connector housing, limits current flow to a safe level in the event the user comes into contact with a high voltage high current source.

Abstract: A receiver for receiving and demodulating FSK modulated data signals has improved sensitivity over substantial frequency offsets between the transmitter and receiver local oscillator, and low spurious electromagnetic radiation. A quadrature coupler splits the received signal into in-phase and quadrature phase signals which are then mixed down to baseband, filtered, and limited. An RC circuit at the output of a four flip flop demodulator averages the flip flop output signals. A voltage comparator outputs a logical 1 if the voltage at the output of the RC averaging circuit is greater than one-half the supply voltage; otherwise the comparator outputs a logical zero.

Abstract: In a circuit arrangement for providing a current having a controllable temperature coefficient of current, a diffused resistor (334) is used to set up a reference current in a current source (40) which has a temperature coefficient dependent upon the diffused resistor. A current mirror (352, 354, 356) receives the reference current and passes a portion of it through an ion implanted resistor (360). The output current has a temperature coefficient which is a function of the original temperature coefficient of current and a nonzero algebraic multiple of the temperature coefficient of the implanted resistor. By appropriate selection of the resistor values and types, the temperature coefficient of the output current can be set to any desired value.

Abstract: A static protective housing includes a plastic housing having an outer wall and an interior. A metallic fastener extends into the housing from the outer wall. A static vault within the housing receives the metallic fastener for insulating the fastener from the housing interior. The static vault is provided with a well portion which receives the fastener and a cover which closes the well portion.

Abstract: An improved electronic clip-on lead is disclosed. It is comprised of an elongated shaft suitable for electrical connection having a front spring finger extending from one end. A rear bracing member is positioned behind and parallel to the front spring finger by a support structure which fixes the displacement of the rear bracing member to the front spring finger.

Abstract: An adjustable active filter includes a transconductance amplifier (60) and a current source (40, 42) which may be adjusted in value. The resonant frequency of the active filter may be adjusted upwards by increasing the bias current of the transconductance amplifier using a frequency trim up network (48). The resonant frequency may be adjusted downward by decreasing the bias current using a frequency trim down network (44). The trim is preferably accomplished by shorting out zener diodes (120, 122, 124, 126, 150, 152) which control the bias current of the transconductance amplifier.