Abstract: A horizontal oscillator for a CRT device runs at a rate higher than the line rate, and has a wide lock-in range. The horizontal sync signal is delayed in an adjustable monostable circuit and coupled to the oscillator for allowing a centering adjustment of one full line. The oscillator output signal is coupled through a discharge circuit for rapid discharge of the subsequent circuit in the CRT device as desired.

Abstract: A low frequency tone detector filters out undesired frequencies in a received signal, than a latching circuit locks on when a given number of low frequency cycles are detected, having at least a predetermined peak amplitude. Thereafter, only a second given number of missing or low amplitude cycles will reset the latch. When the detector determines that the received signal is weak or of very poor quality, false detect signals are essentially prevented. The circuit is particularly suited to use with AM stereophonic signals where a low frequency tone is added to the difference channel for providing mono/stereo indication and mode switching.

Abstract: A charging system for amplifying AC output voltages induced in at least one stator winding of an alternator by residual magnetism from a low carbon steel rotor to self-excite the charging system by means of the residual magnetism at low engine RPM. An electronic voltage regulator is responsive to small AC output voltages from the stator winding, even below voltage levels required to forward bias a silicon semiconductor junction, to fully energize the field winding of the alternator. Since the voltage regulator is responsive to alternator signal developed at low engine RPM, the regulator can also be used as a sensor to indicate an operative engine condition, such as start up.

Abstract: The signal transmitted is a compatible amplitude modulated carrier with amplitude directly proportional to the monaural information or 1+L+R up to a frequency near the upper end of the normal program spectrum. Above the transition region, the amplitude becomes a pure quadrature function. The instantaneous phase varies as a function of the quadrature phase relationship. Transmitter and receiver embodiments are disclosed.

Abstract: A combination radio and tape player is disclosed which includes a signal equalization selector wherein the audio program selection switches which select either an AM or FM radio mode or a tape player mode of operation also simultaneously select various different sets of stored control signals which implement predetermined audio signal equalization in accordance with the type of audio mode of operation (program) that was selected. This is accomplished by the use of a random access memory which stores three pluralities (sets) of control signals, each plurality of control signals corresponding to a predetermined desired equalization for either the AM, FM or tape player modes of operation of the combination radio and tape player. Manual controls are provided which allow selective adjustment of the equalization provided in any of the AM, FM or tape player modes of operation.

Abstract: A low frequency tone detector filters out higher frequencies, then a latching circuit locks on when a given number of low frequency cycles are detected which have at least a predetermined peak amplitude. Thereafter, only a second given number of missing or low amplitude cycles will reset the latch. The circuit is particularly suited to use with AM stereophonic signals where a low frequency tone is added to the difference channel for providing mono/stereo indication and mode switching. The circuit can also provide an early detect for use by a scanning circuit in a receiver.

Abstract: A capacitive pressure transducer 10 with an analog output voltage which varies linearly as a function of sensed pressure is provided. A capacitive pressure sensor C.sub.x provides a pressure variable capacitance that determines the frequency of a sensor oscillator 11. The oscillator frequency is combined with a reference frequency by a pair of D-type flip-flops 18 and 19 to provide a resultant signal having a duty cycle related to the sensed pressure. The resultant signal is integrated to provide a first analog signal as an input to a controllable gain amplifier 24 which receives gain control information from a non-linear gain control circuit 40 that receives an analog control signal as an input. The analog control signal varies as a function of sensed pressure in an opposite manner to said first analog signal. Said non-linear circuit provides for non-linearly varying the gain of amplifier 24 as a function of sensed pressure. Preferably the non-linear circuit 40 includes temperature compensating diodes 47.

Abstract: A mechanical radio receiver tuner with microphonics elimination circuitry is disclosed. During a mechanical tuning mode, the mechanical position of a movable tuning element provides an associated adjustable reactance which determines a control voltage for controlling the output of a voltage controlled oscillator (VCO) that serves as the local oscillator for a superheterodyne radio receiver. After initially selecting a channel frequency by adjusting the output of the VCO with the mechanically movable tuning element in the tuning mode, a switch means disconnects the movable tuning element from operative control of the local oscillator frequency and implements a locked tuning mode by providing the VCO with a control voltage related to the difference between the frequency of the output signal of a mixer stage and the center frequency of a fixed tuned narrow passband IF stage that follows the mixer. Preferably, this control voltage for the locked tuning mode is provided by a phase locked loop.

Abstract: A printed circuit board assembly usable in a transceiver microphone is disclosed. The assembly comprises a first printed circuit board having components mounted thereon which is fixed to one side of a circuit board carrier by retaining tangs. Second and third printed circuit boards also having components thereon are mounted on an opposite side of the circuit board carrier also by retaining tangs. The first circuit board is connected to the second and third circuit boards via pluralities of bare jumper wires extending between end portions of the first circuit board and adjacent end portions of the second and third circuit boards. The carrier is substantially planar and has integral end projections which form associated notches for receiving each of the jumper wires.

Abstract: An electrical switch assembly (10) is provided having upper (11) and lower (12) housing portions which house a dome switch contact assembly (13). A switch actuator (20) substantially comprising a planar oblong plate (21) is mounted to a housing wall (41) of the upper housing portion (11) in a through opening (44) of the housing wall. The actuator (20) forms a hand insertable snap-in subassembly with the wall (41). The actuator (20) is intended for substantially pivotal movement from first to second predetermined positions such that in the second position a contact projection (26) attached to a second longitudinal end portion (25) of the actuator contacts the dome switch assembly (13) while flexible bias tangs (45, 46) apply mechanical bias to the actuator at a first longitudinal end portion (24) to position the actuator toward its first position.

Abstract: A dual slope pulse width modulation regulator for separate control of two independently operative power supplies is provided. An oscillator supplies a triangle wave having a period T signal to each of two separate DC comparators each of which also receives an analog error signal related to the difference between a power supply output signal and a predetermined reference level. The outputs of the DC comparators are coupled to a pair of AND gates which are alternately enabled by a digital output signal of the oscillator with the digital output signal having output states corresponding to the duration of first and second rates of change of the triangle wave signal which occur during each period T. The outputs of the AND gates correspond to pulse width modulated drive signals which are utilized to control the excitation of independently operative power supplies having output sensor circuits which sample the output of the power supplies and result in providing the first and second analog error signals.

Abstract: A regulated automotive alternator battery charging system is disclosed. The system comprises an engine-powered alternator which provides a rectified alternator output signal for charging an automobile battery in accordance with an alternator field coil excitation signal provided by a voltage regulator which senses the battery voltage and alters the field coil excitation in response thereto to maintain the battery in a charged condition. The voltage regulator comprises an oscillator for developing a constant frequency signal which is independent of engine speed and battery load. The regulator includes circuitry for varying the duty cycle of this constant frequency signal in accordance with the sensed magnitude of battery voltage, and the constant frequency but variable duty cycle signal is utilized to provide field coil excitation for the alternator wherein the system maintains the battery voltage at a substantially constant magnitude.

Abstract: Information is derived from two given sets of sensor output pulses relating to crankshaft position for use in determining the proper cylinder to be fired, the spark time and the dwell. The spark is enabled only after the crankshaft position is known, and noise, including the spark itself, is prevented from interfering with the system operation.

Abstract: Field coil current of an alternator is controlled in response to temperature as well as to battery voltage, thus allowing maximum safe output power at any ambient temperature. A monostable circuit is utilized for reducing the maximum duty cycle of the field excitation driver in response to a sensed temperature without increasing power dissipation in the regulator.

Abstract: A method of utilizing anodic bonding to bond a conductive semiconductor wafer to a metallized dielectric glass plate so as to form a capacitive pressure sensing element is disclosed. The method includes positioning the semiconductor wafer in contact with the glass plate, heating the wafer and glass plate and applying a substantial positive DC potential to the semiconductor wafer and metallization on the glass plate while applying a negative DC voltage potential to the glass plate. The glass plate metallization forms one capacitor plate of the capacitive pressure sensing element while the semiconductor wafer forms the other capacitor plate.

Abstract: The circuit determines which cylinder is to be fired and continually updates the determination so that the circuit recovers immediately from any false detect and responds to any change of engine condition. The dwell timing is derived from sensors adjacent the flywheel and, to achieve the widest possible range of advance angles, the use of certain sensor-derived signals is delayed until after spark.

Abstract: An in situ self-diagnostic automotive alternator battery charging system is disclosed. Included are: a battery; voltage regulator sensing battery voltage and generating an excitation signal; and an alternator driven by a vehicle engine provide a rectified electrical signal to charge the battery in response to the excitation signal. Electronic circuit status detectors, variously coupled to the battery, voltage regulator and alternator, maintain a first logic state when a corresponding signal characteristic is within a predetermined range and a second logic state when the corresponding characteristic is outside the predetermined range. Combinatorial logic means respond to a logic state sequence from the detectors to identify predetermined sequences of the logic states resulting in the identification of faults in the charging system.

Abstract: A four-cylinder engine control system (10) for controlling the functions of ignition or fuel injection is disclosed. The control system includes cylinder identification apparatus (30, 50, 60) which operates in conjunction with a rotary member (11) rotated by the engine crankshaft having timing projections (14, 17) corresponding to specific rotational positions of the crankshaft. A pair of fixed sensors (20, 21) sense the passage of the timing projections and provide corresponding signals to an engine timing calculation and control circuit (40) which provides control signals that are sequentially selectively routed to control ignition and/or fuel injection of the engine cylinders in a predetermined sequence. One timing projection (14) comprises two individual radial extensions (15, 16) whereas another comprises a single extension (17).

Abstract: The circuit determines whether an incoming frequency is within the normal "lock-in" range of a phase locked loop VCO or not, and whether it is higher or lower than the VCO frequency. If not within normal range, the beats are rectified and gated to provide a DC control voltage of the proper value and polarity for locking the oscillator on the incoming frequency. Rectification may be half or full wave as needed, and the circuit may include filter bandwidth control as well. This circuit is suitable for signals of any waveform, quadrature signals, and AM stereophonic signals.

Abstract: A decoder for use with a compatible AM stereophonic signal utilizes a amplifier and a feedback loop from the amplifier output to control the output of a multiplier circuit which is one input to the amplifier. The amplifier output is thus forced to become the required correction factor used in restoring the stereo program signals.