Abstract: A side impact sensor processes side acceleration signals and upon a crash event develops a deploy signal which comprises accurately timed pulses of preset duration including a single pulse wake up message and a multiple pulse deploy message. A single wire interface couples the deploy signal to a microprocessor in a central controller which manages deployment of side and frontal air bags and runs frontal impact algorithm. The pulse edges cause interrupts used to measure the pulse widths which are compared to stored values to verify the messages. A wake up pulse causes the microprocessor to give priority to an algorithm for processing the deploy message over the frontal algorithm and still service the frontal algorithm without degradation. Signal drivers in the side impact sensor impose sharp pulse edges for the deploy signal and sloping edges for other signals monitoring the state of health of the side sensor to reduce radiated emissions.

Abstract: An inflatable restraint system includes a diagnostic circuit which measures the resistance of an external deployment path containing a squib. The circuit supplies a test current through the path and measures the voltage across the path which is monitored by a microprocessor. A vehicle battery supplies the power to the system and is connected to a constant current source in series with the external path to provide the test current. A current limiting device between the external circuit and ground comprises a current sink allowing a maximum safe current in the external circuit in the event of inadvertent application of battery voltage to the external circuit and, during a normal resistance test, imposes only a small voltage drop on the test current circuit.

Abstract: Air bags are deployed by firing circuits each containing a squib in series with a common control switch, and a control containing an accelerometer and a microprocessor for operating the switch to deploy the air bags. To diagnose shorts, a current source feeds a trickle current through each squib and a current limited voltage regulator across the switch passes the combined trickle currents to ground. The microprocessor senses the voltage across the switch via an A/D converter. That voltage goes low for a short to ground and high for a short to battery voltage.

Abstract: A supplemental inflatable restraint deployment system comprises an energy reserve capacitor, a first supplemental inflatable restraint deployment circuit comprising a controllable current source in series with a first squib, a second supplemental inflatable restraint circuit comprising a second controllable current source in series with a second deployment squib and a control unit for providing a first pulse of first duration to the first controllable current source to activate the first squib and for providing a second pulse of second predetermined duration to the second controllable current source to activate the second squib, wherein the first and second pulses are staggered with respect to each other.

Abstract: Large reserve capacitors store energy sufficient to operate the firing circuit and the deployment circuit for an SIR in the event of loss of battery or ignition voltage in a crash. A voltage doubling or tripling circuit charges the reserve capacitors. Normally the capacitors are isolated from the deployment circuit to minimize the load on the charging circuit. An isolation circuit detects the loss of ignition voltage and then connects a reserve capacitor to the deployment circuit for continued control operation.

Abstract: The invention provides frequency multiplier circuitry which may be used in the output section of high power microwave systems to efficiently provide higher output frequencies. Generally, one multiplier stage may be utilized to double the frequency of the input signal with several stages being cascaded to achieve even higher frequencies. The varactor diodes utilized in circuits of the invention are preferably constructed primarily of silicon carbide, which has many advantages when compared with current varactors constructed of GaAs or silicon. Some presently preferred embodiments utilize a four terminal varactor bridge instead of a single varactor diode. The invention also teaches several significant techniques for improving the bandwidth of the circuitry, thus allowing variation of the frequency of the input signal without significantly attenuating the output signal.

Abstract: Push-pull complimentary MOSFET devices are formed in a thin active layer between the top surface of a high resistivity silicon wafer and a insulating layer implanted below the top surface. Each MOSFET is composed of a plurality of cells each having a source, a gate, and a drain region extending fully through the active layer. Grooves extending through the wafer are lined with vias which connect the source regions with a floating ground plane on the bottom of the wafer. The gates of all the cells are connected by a gate bus on the top surface. Air bridges spanning the gates and the source vias connect the drain conductors of each cell. Neutralizing capacitors connected between an input and an opposite output of the push-pull complimentary MOSFET devices match the parasitic capacitances of the devices and provide wide bandwidth amplification with roll off well into the GHz range without the need for tuning inductors.

Abstract: A dual mode electronic identification system using a tag which has a RF receiver and transmitter contained therein. In the first mode the tag responds to an interrogation signal by transmitting identification data to the interrogator. In the second mode the tag periodically transmits an identification beacon signal to a directional sensing antenna which uses the signal to compute the position of the tag. The power supply for the tag operates from an internal battery or from power received from a portal signal via a tag receiving antenna. The battery can be automatically turned off when the tag is in the portal area and the unit can be shifted into the battery operated beacon mode when the tag is removed from the portal area.

Abstract: A melt replenishment system for dendritic web growth having a pellet feed arrangement, which distributes equal amounts of feed material to a pair of feed tubes in communication with opposite ends of a crucible to maintain a melt pool at a constant level and a cover gas system, which keeps the feed tubes flowing and helps maintain thermal consistency within the melt.

Abstract: An elevator system including an elevator car to be stopped at a predetermined stopping point from any initial speed below a predetermined maximum value, at a predetermined uniform rate of deceleration. The uniform rate of deceleration determines the desired speed versus distance-to-go reference pattern, which is initiated at a predetermined fixed distance from the stopping point. If the car speed is at the maximum value, deceleration will be initiated immediately. If the car speed is below the maximum value, the car is allowed to continue at the same speed until the car speed and location of the car relative to the stopping point match a point on the reference pattern. This point is accurately determined via digital feedback and comparison circuits which start the elevator car on the desired deceleration speed pattern with zero error.

Abstract: A DC pulse generator, specifically suitable for application as a cardiac pacemaker having a substantially constant energy output which is independent of the output load. The output pulse is derived from a capacitive reactance which is partially discharged to a preselected reference level. The cyclic rate of discharge is maintained substantially constant, and accordingly, the pulse width is varied to assure a constant energy output to the load. The capacitive reactance is charged in between output pulse periods from a matched impedance radioisotope thermoelectric source through a constant current inverter, step-up transformer, voltage doubler, inverter network. The oscillator controlling cyclic discharge of the capacitance through the load and the inverter, which is arranged in a push-pull configuration, is designed to be self-starting to avoid stall conditions during operation. Furthermore, the discharge rate is substantially independent of the DC level and provides a negative rectangular output pulse.