Abstract: A clamping and ejecting assembly for a support structure for an autoradio or the like is disclosed. A box shaped container is adapted to receive and firmly support a removable apparatus such as an autoradio or tape player having a complimentary clamping means provided on it. A spring element is mounted to the bottom of the box shaped container and is reciprocally movable with respect to the container between a first retracted position and a second extracted position. Clamping means are provided on the spring element and project into a central receiving cavity of the box shaped container through an opening in the bottom of the container to matingly engage the complimentary clamping means on the inserted apparatus and thereby maintain the apparatus firmly inserted in the support container when the spring element is held in its first retracted position.

Abstract: An improved adjustable rotary position sensor assembly is disclosed which is adaptable for sensing the rotational position of a body being synchronously rotated by an engine crankshaft and producing spark timing signals for the engine in response to the rotational position of the body. A generally cylindrically shaped Hall sensor probe is mounted through a cylindrical bore in an engine block and positioned such that one end of the sensor probe will be adjacent to radially extending portions of the rotary body during the rotation of the body by the engine. The Hall probe is rotatably adjustable with respect to the central axis of its cylindrically shaped body. A slotted mounting flange is attached to one end of the Hall probe and together with a retaining screw provides for locking the probe into a fixed rotational position with respect to its central axis after it has been adjusted.

Abstract: A rotary direction sensor used in conjunction with an engine spark ignition system is disclosed. Two sensors are used to sense the rotational position of a rotary body which is being synchronously rotated by the crankshaft of an internal combustion engine. Output signals of the sensors are compared by a logic circuit which produces ignition spark timing signals in response to the rotation of the rotary body in a predetermined direction. These spark timing signals are subsequently used to trigger SCRs which apply a high voltage across an ignition coil and thereby cause an ignition spark in a cylinder of the internal combustion engine. The sensors, the rotary body and the logic circuit are constructed so that engine spark timing signals are only produced for the internal combustion engine when the rotary body is rotated in a given rotary direction. Thus the generation of cylinder spark ignitions when the engine is being rotated in a reverse direction is inhibited.

Abstract: A variable resistance pressure transducer having high resolution, a wide resistance range and usable in conjunction with a limited linear actuation movement is provided. The transducer basically comprises a helical resistance element and a circular ring shaped contact arm which are mounted around a central axis and are slideably movable with respect to each other in directions parallel to the central axis. The ring contact essentially forms the wiper arm of a potentiometer assembly and the ring is dimensioned and positioned so that varying portions of its inner circumferential surface will contact the resistive element during relative linear axial movement between the ring and resistive element. This results in moving the effective point of contact between the ring and resistive element continously along the surface of the helical resistive element in response to the relative axial movement.

Abstract: A spark timing circuit for use with the ignition system of an internal combustion engine is disclosed. Two sensors produce periodic digital logic signals which have frequencies related to the speed of the engine rotation and which differ by a predetermined amount of phase. These signals are coupled as inputs to a first exclusive OR gate which produces an output signal having logic states which correspond to the coincidence and non-coincidence of the logic states of the two input signals, the duration of one of the logic states of the output signal therefore being directly related to the phase difference between the first and second sensor signals. An adjustable pulse generator circuit then receives this output signal and produces a new corresponding synchronized digitial output signal having the duration of one of its logic states equal to an adjustable proportion of the phase difference logic state duration of the first exclusive OR gate output signal.

Abstract: A tape recorder/player includes several slideable mode selector control levers for selecting the reproducing, recording, stop and other modes of operation of the player. To prevent operation of these levers when the cassette or tape is not in the player, a slideable cam plate is provided, which in a first position engages projections on the levers to prevent them from being moved into their operative positions. In a second position, a number of slots in the cam plate are aligned with the projections on the control levers to permit their movement to select the desired function. A solenoid is energized whenever a cassette or tape is inserted into the recorder/player and controls movement of the cam plate to its second position to align the aperatures with the projections of the levers to permit their operation. When the cassette or tape is removed from the player, the solenoid is de-energized returning the cam plate to the first position where it prevents operation of the control levers.

Abstract: A monostable multivibrator circuit is disclosed which uses a feedback diode to couple the output signal of the monostable back to one terminal of the timing capacitor and thereby maintain the voltage at this capacitor terminal at a constant level for a duration equal to the pulse duration of the monostable output. A transistorized internal combustion engine ignition system is illustrated which incorporates the diode feedback monostable circuit. A trigger input signal actuates a first transistor switch which creates an abrupt negative transition that is coupled across a timing capacitor and results in turning off a second transistor for a predetermined amount of time. A third transistor monitors and inverts the output of the second transistor and produces an output signal at its collector. This inverted output signal forms the output of the monostable multivibrator and this signal is fed back to one terminal of the timing capacitor by a feedback diode.

Abstract: A device for preventing a tape cartridge from springing out from the cartridge entryway of a tape player upon cartridge ejection operation. This device includes a sliding member having one end provided with a roller projection into the cartridge entryway. The sliding member is adapted to slide on an inclined face so that the amount of the roller projecting into the cartridge entryway will increase as the roller and sliding member moves toward the insertion opening of the cartridge entryway, whereby the roller exerts a retaining pressure on the cartridge which increases as the cartridge moves toward the insertion opening of the entryway during cartridge ejection.

Abstract: A sub-assembly package which includes a bushing, a fly-wheel, and a capstan for use in a playback and/or recording apparatus. The fly-wheel is locked to one end of the capstan which is supported by the bushing, and the package is removably fixed to a supporting frame by a single nut.

Abstract: A selective threshold ignition circuit adaptable for use in an electronic ignition system for an engine is disclosed. A magnetic pick-up produces an AC signal about a DC reference level which has a frequency related to the rotational movement produced by the engine. A circuit receives this AC signal and produces a corresponding spark timing signal by comparing the AC signal with a DC threshold level. A selector circuit chooses a first DC threshold level for the comparing circuit which is effectively equal to the DC reference level during the period of engine start up. The selector circuit chooses a second DC threshold level which is different from the DC reference level when the engine is running and before the engine has been started. By providing a threshold level equal to the DC reference level during the engine start up mode of operation, an accurate ignition timing signal is produced during this critical period.

Abstract: An improved circuit for producing a signal indicative of an input signal floor level is disclosed for use in determining the noise level of an audio signal in a receiver voting system. An input audio signal which contains noise is amplified by variable gain amplifier circuitry consisting of a constant gain amplifier and a variable attenuator. Detector circuitry then develops a signal which is indicative of the noise level, this signal substantially corresponding to the minimum peak magnitude of the amplified input audio signal. During pauses between audio tones in the input audio signal, this minimum signal magnitude coincides the residual background noise level of the input audio signal. Control circuitry couples the noise level indicative signal to the variable attenuator and constitutes a negative feedback loop for inversely and nonlinearly varying the amplification of the input signal in response to the magnitude of the noise indicative signal.

Abstract: A magnetic head lifting device for a tape recorder is disclosed in which the turning force of a capstan shaft is used as a drive source for the head lifting device. The device includes a rotary body having indented portions in a peripheral edge, a ring attached to a capstan shaft and engageable with the nonindented portions of the peripheral edge of the rotary body, a rotary body urging member, a rotary body stopping member, an electromagnet, an antiexcessive rotation member positioned by the electromagnet to positively prevent excessive rotation of the rotary body, and a stepped surface cam associated with said rotary body for lifting the magnetic head in response to the rotation of the rotary body. The head lifting device provides a positive engagement and disengagement between the capstan shaft and the rotary body and prevents any malfunction due to an excessive rotation of the rotary body by the capstan shaft. The device is miniaturized since only a small capacity electromagnet is required.

Abstract: A change-over mechanism for a pushbutton radio tuner is disclosed. The mechanism has a tuning shaft which transmits rotational movement to a pinion shaft in engagement with a crown gear. The tuning shaft is slidably and rotatably mounted on a frame body. The sliding movement of the tuning shaft enables a switch to be changed-over while the rotational movement enables a tuning operation to be effected.

Abstract: A combined encoder and decoder circuit which uses a single frequency selective resonant reed in a closed loop oscillator configuraion permitting simultaneous encoder and decoder operation. A closed loop oscillator has a resonant reed connected in series between an input and output terminal and produces a signal at the resonant frequency of the reed. Positive signal feedback from the output to input terminal is provided by an amplifier, operated between saturation and cut-off, and a controllable attenuator. A level detector and the attenuator effectively form a limited range negative feedback loop which effectively maintains the signal magnitude at the output terminal at a substantially constant level.

Abstract: A stereo inhibit circuit adaptable for use in an FM stereo radio having a stereo indicating light is disclosed. A level detector and a mute circuit develop a mute signal which is related to the amount of signal noise at the output of an FM detector. This mute signal is used to inhibit a stereo switch that controls the stereo indicating light while permitting the creation of audible signals by a stereo demodulator and a pair of speakers. Thus the stereo inhibit circuit permits the creation of an audible hiss and positively prevents any flickering of the stereo indicating light when the FM radio is not tuned to a station.

Abstract: The IF amplifier combines the high frequency and low noise figure characteristics of a cascode stage with the large signal handling capability and accurate gain control of a direct emitter coupled amplifier controlled by a constant current source. The amplifier uses a technique of alternately stacked cascode stages which results in minimizing both the total current drain and the value of DC potential necessary to operate the amplifier. A current mirror, independent of power supply variation, is used to control the gain of the amplifier and is also used to provide temperature compensation for amplifier gain. Special bias techniques along with the current mirror minimize the variation of the amplifier gain with respect to DC power supply variations. Novel use of semiconductor devices minimizes the number of leadout connections on an I.C. chip needed for attaching large external bypass capacitors.

Abstract: A hand-insertable, hand-removable electrical contact assembly is disclosed, which requires no special mounting tools or additional mounting components. The electrical contact assembly is especially adaptable for use in conjunction with battery charger apparatus, or the like. In one embodiment, a resilient contact arm or element having a reduced midsection is adapted for insertion into an associated slot in the assembly casing. The contact arm is inserted by bending it at the resilient midsection while sliding one end section of the contact arm into the casing slot. When the contact arm is released, the resiliency of the midsection causes the other end section of the contact arm to press against the surface of the casing and thereby lock the contact arm within the casing. The assembled contact element is readily removable by simply reversing the above procedure.

Abstract: High frequency power transistor carriers are made by bonding a metalized ceramic base to a lead frame strip, cutting the lead frame strip to isolate the base and collector leads while still maintaining the transistor carriers in strip form, and subsequently gold plating the resultant structure. Transistor dice are then attached to each ceramic carrier, and each transistor carrier in the strip is then electrically tested. The individual carriers are then separated from the lead frame strip. The individual carrier has wide base and collector leads extending outward from the ceramic base for a substantial distance and then the base and collector leads are narrowed down. When the individual transistor carrier is used in combination with a hybrid assembly, a reduction in lead inductance and total hybrid package size is obtained while exact carrier placement relative to the hybrid assembly is not required.

Abstract: An improved balanced dual output diode mixer circuit having separate output terminals for audio and RF output signals is disclosed. The mixer circuit includes a first transformer having a primary and a center tapped secondary winding. The ends of the secondary winding are coupled to end terminals of two separate secondary windings of a second transformer through a switching circuit which comprises four diodes. RF bypass capacitors are coupled between an RF terminal and end terminals of the secondary windings of the second transformer and provide a low RF and a high audio impedance therebetween. RF chokes are coupled between audio output terminals and the RF bypass capacitors and provide a low impedance audio path which is connected at a point of low RF impedance. A pair of resistors coupled between ground and the RF bypass capacitors provide a DC current path to ground for the rectified DC current created by the switching network.