General Datacomm, Inc.

Other

Welles K Reymond

Gregory L Sorrentino

An active acoustic intrusion detection system includes a pair of dipole emitters (180 degrees out of phase with each other) which emit an audible frequency f (preferably 1 KHz) and a pair of detectors preferably mounted &#xbc; wavelength (3 inches) apart in the (non-echoic) nulls of the emitters. The detectors (microphones) spatially sample a stationary wave which is generated by the emitters (speakers). The output of each microphone is fed to an ADC and the digital output of the two ADCs is used to generate a four dimensional vector. At startup, a reference vector is determined and stored. During operation, vectors are sampled, filtered, smoothed and averaged periodically. When an average vector deviates from the reference vector by a set amount, an alarm is generated.

Acoustic intrusion detection system

An inductor element comprises a copper pattern on a PCB on which a magnetic powder is deposited. The inductor is formed according to the method of the invention by etching a copper layer of a PCB in a desired pattern. A magnetic powder-loaded ink is then screened or stenciled over the pattern of the inductor elements etched in the copper layer of the PCB. The resulting inductor element is enhanced, having increased low frequency inductance and increased high frequency loss. Multiple inductor elements may be formed on a single PCB in a single process without requiring further cost or steps in the method.

Method for generating enhanced etched inductor elements

An LED array circuit includes a number of series connected LED pairs, each pair including two parallel connected oppositely polarized LEDS. The array is coupled to a standard AC voltage source in series with an inductor L having Q&gt;5 and a reactance which is equivalent to the resistance of a current limiting resistor. The use of an inductor in place of a resistor increases the efficiency of the array to approximately 80%. The efficiency of the array is increased even further by coupling a capacitor parallel to the array and by tuning the inductor and capacitor to the frequency of the AC voltage source. According to one embodiment of the invention, a somg;e retro-fittable unit is provided wherein an inductor, a capacitor, and an array of LEDs are contained in a housing having substantially the same size and shape as a standard incandescent bulb or the lens/filter used in a traffic signal display. According to another embodiment of the invention, a single module is provided with a plurality of LED arrays, with each LED array having its own capacitor coupled in parallel thereto, and its own series coupled switch. The module is coupled to and across the AC voltage source, with one node of the module coupled to the AC voltage source by an inductor.

AC powered light emitting diode array circuits for use in traffic signal

A high speed synchronous digital bidirectional data bus system is provided and includes an M-bit unterminated data bus, an unterminated standing sine wave clock bus, and a plurality of integrated circuit bus interfaces. Each IC bus interface is preferably substantially incorporated on a single CMOS LSI chip and includes M bus drivers with associated send data logic, M data receivers with associated receive data logic, and a clock receiver. The output currents of the bus drivers on all of the chips are preferably stabilized so that each driver drives the bus at substantially the same output current. The drivers are preferably complementary polar driven CMOS logic elements. For this case, for each data receiver, a bus keeper is coupled to the output and the input of the bus receiver to maintain the last state of the data bus. In addition, the clock receivers and the data receivers are embodied as high speed comparators having internal hysteresis. The clock receivers are preferably provided with a delay generator which produces a 'guard band' during which the bus drivers are tri-stated before they can drive the data bus. This prevents conflicts on the bus and guarantees end sampling of data.

High speed synchronous digital data bus system having unterminated data

An isolated, high impedance, DC current source is provided from a readily available AC type source. The DC current source includes an isolating transformer which receives the AC source signal and provides an isolated AC voltage signal therefrom, a resonant low pass filter which is tuned to the frequency of the AC type source and which takes the AC isolated voltage signal and generates therefrom an AC current source signal, and a rectifier which rectifies the AC current source signal to provide a DC current source signal. A voltage limiting clamp is preferably coupled to the rectifier in order to limit the output voltage to a desired level. The resonant low pass filter is preferably comprised of two substantially equally valued inductors coupled to respective poles of the secondary winding of the isolating transformer, and a capacitor which is coupled to both of the inductors. In one embodiment, the AC type source is a 5 V CMOS clock signal, and the output current source generates a sealing current of between 4 and 10 milliamps for telecommunications equipment. In another embodiment, the AC type source is chosen for a desired voltage and frequency, and a plurality of DC current source circuits are coupled to the AC type source in order to distribute power to repeaters or other remote equipment.

Isolated high impedance, DC current sources for telecommunications

A clock phase and frequency distribution system is disclosed which uses a standing sine wave and provides substantially simultaneous significant crossing instances everywhere in the system while using low power and not requiring bus termination or precise control of transmission path characteristics (Z.sub.0). The system is particularly advantageous in high frequency applications such as digital, linear (non-branched), backplane applications, but is also applicable to other topographies such as stars, rings, and meshes. The system includes a sine wave generating and driving circuit, a clock bus, and clock receivers. The clock receivers present a high impedance interface to the clock bus. The basic design considerations and parameters which limit and define performance include the maximum propagation delay between any two points in the system, the total low frequency capacitance of the system, and the Q of the system which must be high at the frequency of the standing wave in order to satisfy low power and simultaneity objectives. To overcome system length limitations, embodiments utilizing master and slaves are provided, where phase feedback is provided to the slaves. Multifrequency systems are also provided.

Standing sine wave clock bus for clock distribution systems

Output characteristics of CMOS chips are controlled by providing a known and stable current to a representative transistor of known relative size in the CMOS chip, and arranging the output CMOS driving transistor(s) of the chip, which are of known size relative to the representative transistor, in current mirror relationship with the representative transistor. Two primary embodiments of the invention are provided. In a first primary embodiment (I.sub.d,SAT stabilization), the representative transistor is a diode-connected transistor with a saturation current which is generated by the current source and which is also provided to drive the output transistor device(s) when it is ON. In the second primary embodiment (R.sub.ON stabilization), instead of being diode-connected, a servo is used to adjust the gate voltage of the representative device until it is greater than the drain voltage by a desired amount. In this manner, the resistance (R.sub.ON) characteristics of the representative device and hence the driving transistors are controlled. The invention has particular applicability to driving unterminated buses, and I.sub.d,SAT embodiment can be arranged to provide complementary output bus driving transistors. Because similar known and stable currents are generated on different semiconductor chips, the driving currents of the output devices of the different chips will be similar.

Output characteristics stabilization of CMOS devices

A connector system having an electrical switch capability for connecting a first electrical conductor to a second electrical conductor is provided and includes a spring biased contact element having a first portion for making electrical contact with the first electrical conductor, a second tapered contact portion for mating with a conductive rim of a hole of the second conductor, and a spring portion for biasing the tapered contact portion in the closed position where the second tapered contact portion mates with the conductive rim, and an actuation member for bringing the tapered contact portion into the open position. The actuation member may be a plunger or the like which enters the hole with which the tapered contact portion is mated from the rear side and pushes the tapered contact portion out of contact. The actuation member may have its own electrical characteristics for test purposes, and may be insulated just for opening the circuit, or appropriately insulating and conductive to form a new circuit path. The actuation member may make electrical contact with either the tapered contact portion or the conductive rim either before or after the connection between the tapered contact and the conductive rim is broken. The connector system typically connects several first conductors with several respective second conductors and allows selective switching/testing of one or more individual connections without disturbing the other connections.

Connector system having switching and testing functions using tapered

A transformed current sensing relay with reduced AC impedance of the operating coil is accomplished by adding a shorted secondary winding to an otherwise conventional current sensing reed relay. The shorted secondary winding is preferably implemented with a copper tube over the existing coil and inside the magnetic circuit. This transformed current sensing relay is particularly advantageous for the line current sensing function in switched network communications equipment such as high speed modems, where the transformed relay exhibits substantially lower impedance at high frequencies than the conventional current sensing relay. This transformed current sensing relay allows for the elimination of bypass capacitors and results in significant cost and space savings. Moreover, the transformer nature of the transformed current sensing relay allows for the elimination of suppression resistors from the interface resulting in additional cost and space savings.

Transformed current sensing relay for use in switched network modems and

A contact element for an electrical connector or an integrated circuit which is used with a hold-down mechanism has a base portion, a spring portion having at least partially helical spring elements, and a tapered contact portion which mates in a biased manner with the conductive rim of a hole. The contact element is particularly useful for surface mount applications. The spring portion is preferably arranged with a partially helical spring configuration so that compression of the spring also effects a torsional rotation of the contact portion. The contact element can be fabricated from: a flat sheet with punching, rolling, and/or forming operations, thin walled drawn parts, or modular parts. Additionally, spring sections may be arranged in tandem, in either a co-rotational or counter-rotational manner to provide additional degrees of design freedom with respect to compression range, axial spring rate, and rotational rate. Contact elements can be associated with insulating housings and/or spacers which provide functions such as alignment, compression limitation, contact support, and installation fixturing. In a preferred embodiment the contact portion has a non-linear taper which permits the normal mating force to be well defined regardless of the diameter of the conductive rim of the hole.

Spring biased tapered contact elements for electrical connectors and

A pluggable electrical connector is provided having contact elements with first ends soldered to a daughter board, mid-sections which are crimped and bent through ninety degrees, and second ends which have a converging portion and which terminate in bifurcated conical contact portions which make contact with the rims of contact-quality plated through holes of a mother board. By causing contact between the rim and the cone surface, normal forces greater than the mating force are generated. The connector housing includes self-centering funnel openings adjacent the mother board for centering the converging portions of the contact elements therein in a nominal position and for acting as a preloading stop. The housing also includes side-wall locking tabs which hold adjacent rows of contacts at identical fixing points relative to the ninety-degree bend to ensure identical spring parameters for all contact elements. By arranging the housing properly, the contact elements can be manufactured into preloaded spring contacts during assembly by bending and locking the first ends of the contacts past the side-wall locking tabs. Cams or retracting bars can be used with rows or individual contacts to create a ZIF connector and/or a selectively engaged pin enabled connector. Magnets, spring-loaded jack screws, or the like are used in conjunction with the connector to establish and maintain force during mating.

Electrical connectors for direct connection to plated through holes in

Electrical connectors are provided with spring contact elements each having a tapered contact portion for mating with the plated rim of a hole. The tapered contact portion can be configured as a bifurcated cone, a suitably shaped wire, or other tapered, flexible contact. Besides the contact portion, the contact elements also include spring portions which can assume various configurations and tail portions which can also assume various configurations. Where the tapered contact portion is a suitably shaped wire, the spring portion and the contact portion are essentially the same. The tail portions can be arranged to have tapered contact portions where permanent connection of the tail is not desired. The disclosed electrical connectors have housings for the spring contact elements, and a first make, last break function can be provided by configuring the housings appropriately. The holes with which the tapered spring contact elements mate can be part of a printed circuit board, a flex circuit, or other object.

Electrical connectors having tapered spring contact elements for direct

An integrated circuit package is provided with a plurality of contact element leads, each lead having a first portion for making electrical connection with the integrated circuit and a second tapered contact portion for mating with a conductive rim of the hole of a circuit board. In conjunction with the integrated circuit package, a fastener is provided for holding the tapered contact elements in mating relationship with the conductive rims. The tapered contact portion of the lead of the integrated circuit package may take any of various forms, as long as the lead is tapered and resilient so that proper mating with a conductive rim can be accomplished. Likewise, the fastener which holds the tapered contact elements in mating relationship with the conductive rims may take any of numerous forms. All that is required is that the fastener couple to both the circuit board and the integrated circuit package, and that the integrated circuit package be removable from the fastener.

Integrated circuit packages using tapered spring contact leads for

A pluggable electrical connector is provided having contact elements with first ends soldered to a daughter board, midsections which are crimped and bent through ninety degrees, and second ends which have a converging portion and which terminate in bifurcated conical contact portions which make contact with the rims of contact-quality plated through holes of a mother board. By causing contact between the rim and the cone surface, normal forces greater than the mating force are generated. The connector housing includes self-centering funnel openings adjacent the mother board for centering the converging portions of the contact elements therein in a nominal position and for acting as a preloading stop. The housing also includes side-wall locking tabs which hold adjacent rows of contacts at identical fixing points relative to the ninety-degree bend to ensure identical spring parameters for all contact elements. By arranging the housing properly, the contact elements can be manufactured into preloaded spring contacts during assembly by bending and locking the first ends of the contacts past the side-wall locking tabs. Cams or retracting bars can be used with rows or individual contacts to create a ZIF connector and/or a selectively engaged pin enabled connector. Magnets, springloaded jack screws, or the like are used in conjunction with the connector to establish and maintain force during mating.

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Waterbury, CT, United States of America

Welles K Reymond