Abstract: An improved demagnetizer for the magnetic heads of a tape cassette recording and/or reproducing device. The device includes an intermediate gear which is rotated by either one of two hub gears engaging respective drive spindles of the recording and/or reproducing device. A push-pull rod has one end pivotally connected to an outer radial position of the intermediate gear and another end pivotally connected to a generator of an alternating magnetic field of constant intensity. Power is supplied from a battery to the generator of an alternating magnetic field upon closure of a power switch caused by motion of the magnetic head into the "play" position. Rotation of the intermediate gear causes the magnetic field generator to be cyclically and linearly reciprocated with respect to the head so as to produce a varying magnetic field at the head. A sensor senses when the magnetic field generator has been reciprocated to its farthest point from the head and a circuit counts the number of such sensings.

Abstract: This invention discloses a wireless compact disc stereo playback system for use in automobiles. An FM transmitter is employed which is connected at the output of a portable CD player, the FM transmitter thereby producing a stereo FM signal which is transmitted to be received by the automobile antenna. The automobile's FM system is tuned to play the output of the CD player through the FM radio system of the automobile. The output power of the FM transmitter and its bandwidth are selected so that the distance from the antenna to the FM transmitter will be sufficient to ensure effective sound production in standard automobiles and vans.

Abstract: A pulse width modulated DC to DC voltage converter for producing selectable differential output voltages. A feedback voltage and a selectable error voltage are fed back to the controller to control the pulse width by the difference between them. First and second power switches are respectively operable in response to first and second square wave signals output from the controller. The converter includes a center-tapped transformer having first and second output terminals. The outputs from the first and second output terminals are filtered and rectified into respective nominally positive and negative DC output voltages. A first selector switch for selectively connecting the nominally negative voltage output terminal to either a grounded bus or a negative bus is mechanically ganged to a second selector switch having a plurality of positions for selecting one of a plurality of predetermined error voltages.

Abstract: A wireless local transmission system includes a separate transmitter and receiver. The transmitter converts an audio signal and/or an audio and video signal into a modulated signal within the 902-928 MHz frequency band and transmits the modulated signal to the receiver which reconverts the modulated signal to a frequency band below 900 MHz for use by a radio or television receiver.

Abstract: A repeater for receiving data transmitted thereto via a first transmission medium, transmitting that data over AC power lines to a remote location and re-transmitting that data from the remote location via a second transmission medium. The data is applied to the AC power lines by frequency modulating an FM carrier and supplying that modulated carrier to the power lines by way of a bandwidth limiting circuit. At the remote location, a resonant circuit in combination with a reject circuit receives the modulated FM carrier from the AC power lines and passes only an extremely limited band of FM signals to a tuned amplifier which, in turn, supplies the band-limited FM signals to a demodulator.

Abstract: A device comprised of separate transmitter and receiver sections, which converts an audio signal into an FM signal, transmits the FM signal over AC power lines, and reconverts the FM signal into an audio signal, which can then be outputted to loudspeakers or other devices. By transmitting the signal over AC lines, no long wires are needed to connect remote loudspeakers or other devices to the source of the audio signal.

Abstract: A simple and inexpensive demagnetizer for the magnetic heads of a tape cassette recording and/or reproducing device includes an intermediate gear which is rotated by either one of two hub gears engaging respective drive spindles of the recording and/or reproducing device. A push-pull rod has one end pivotally connected to an outer radial position of the intermediate gear and another end pivotally connected to a source of alternating magnetic field of constant intensity. Rotation of the intermediate gear causes the magnetic field generator to be cylically and linearly reciprocated with respect to the head so as to produce a decreasing magnetic field at the head.

Abstract: A device comprised of separate transmitter and receiver sections, which converts an audio signal into an F.M. signal, transmits the F.M. signal over A.C. power lines, and reconverts the F.M. signal into an audio signal, which can then be outputted to loudspeakers or other devices. By transmitting the signal over A.C. lines, no long wires are needed to connect remote loudspeakers or other devices to the source of the audio signal.

Abstract: A cleaning apparatus for cleaning the heads of tape player/recorder units in which, when the cleaning apparatus is operably loaded into the unit, movement of the pinch roller and capstan of the unit turns a cleaning element positioned against the head. Transmission of the rotary movement of the pinch roller and capstan is achieved by a rotatably mounted drive belt connected to a cleaning element, such as a felt pad, so that as the pinch roller and capstan rotate, the belt is driven, thus causing the cleaning element to be rotated against the head about an axis substantially perpendicular to the plane of the face of the head of the unit. A tape drive cleaning assembly is included which cleans the pinch roller and capstan of the unit when the cleaning apparatus is turned upside down.

Abstract: Cleaning apparatus for a compact disc comprises a housing having a hingedly coupled base and cover; a drive wheel disposed in the base of the housing rotatably supporting the compact disc and having a first axis of rotation, a rotatable carrier fixed to the cover and having a second axis of rotation and further having a cleaning pad fastened thereto which is adapted to contact the surface of the compact disc to clean the same, and a drive element coupled to the drive wheel and the carrier for rotating the compact disc and cleaning pad at approximately the same speed.

Abstract: An adapter is provided for use with a television receiver to detect and decode stereophonic audio signals, SAP signals or auxiliary signals that may be transmitted with the composite television signals. The adapter includes an IF input that is physically separate from the television receiver for receiving IF audio signals that normally are derived from the transmitted composite telephone signals. Detecting circuitry is coupled to the IF input by means of a tuned circuit that is tuned to the IF carrier frequency of the received IF audio signals for detecting the stereo, SAP or auxiliary signals transmitted with the composite television signals. The detected signals are used to drive utilization means, such as loudspeakers. Preferably, switches are provided to select the stereo or SAP or auxiliary signals for detection.

Abstract: An adapter for enabling the signals produced by one type of playback device, such as a compact disc player, to be reproduced as audio sounds by a cassette player audio system, the latter having a conventional cassette playback deck. The adapter is comprised of a housing having a configuration substantially identical to the configuration of a cassette normally used with the playback deck. The adapter housing has at least one opening to receive the usual reel-drive spindle of the playback deck; and a record head is supported in the housing in a position for contacting the usual playback head of the deck when the adapter is received, or loaded into that deck. The adapter is connected to the playback device (e.g. the compact disc player) by a plug connected to the usual headphone jack of the player, whereby signals produced by the player are supplied to the record head from which they are coupled to the playback head of the cassette deck for reproduction by the audio system.

Abstract: A cleaning apparatus for cleaning the heads of tape player/recorder units in which, when the cleaning apparatus is operably loaded into the unit, movement of a spindle of the unit turns a cleaning element positioned against the head. Transmission of the rotary movement of the spindle is achieved by a rotatably mounted drive connected to a cleaning element, such as a felt pad, so that as the spindle rotates, the cleaning element is rotated against the head about an axis substantially perpendicular to the plane of the face of the head of the unit. A tape drive cleaning assembly is included which cleans the pinch roller and capstan of the unit.

Abstract: Cleaning apparatus for a compact disc comprises a housing, a rotatable carrier disposed in the housing, a cleaning pad fastened to the carrier for contacting the surface of the compact disc, a drive wheel for driving the carrier to rotate the latter about an axis of rotation and concurrently to cause that axis of rotation to move along a predetermined path, and a constraint for constraining that path of movement to a curved path, whereby the carrier and its cleaning pad exhibit planetary movement of both rotation and revolution.

Abstract: A television stereo adapter is provided for use with a television receiver to detect and decode stereophonic audio signals that may be transmitted with the composite television signals. The adapter includes an IF pick-up that is physically separate from the television receiver for picking up spurious IF audio signals that normally are generated by the television receiver. A stereo detector is coupled to the IF pick-up for detecting from the IF audio signals monophonic and stereophonic components that are transmitted with the composite television signals. The detected components are decoded into left-channel and right-channel audio signals; and these left-channel and right-channel signals are adapted to drive sound transducers, such as loudspeakers. Optionally, the left-channel and right-channel audio signals are amplified by gain-controlled amplifiers whose gains are a function of the output sound level of the television receiver.

Abstract: An improved video synchronizing signal separator for separating luminance and synchronizing signal components, respectively, from a composite video signal. Separate luminance and synchronizing channels are supplied with the composite video signal, each channel including a biased diode and an output attenuator. The diodes are poled in opposite directions to conduct when the particular threshold level established by the bias voltage applied thereto is exceeded. As an example, the diode in the luminance channel may be positively poled to conduct when the luminance signal component exceeds a positive threshold level and the diode in the synchronizing channel may be negatively poled to conduct when the synchronizing signal component exceeds a negative threshold level. The positive-going luminance signal component serves to cut off the diode in the synchronizing channel and the negative-going synchronizing signal component serves to cut off the diode in the luminance channel.