Abstract: To provide recognition of personal data, for example the registration number of a vehicle in which a car radio is installed, the car radio includes a non-volatile memory (4) which can be selectively connected to a data input arrangement (2) for the electronic equipment (1) to store the registration number therein. A recall switch (S2) is provided to selectively connect the non-volatile memory (4) to the display (3) for displaying the personal recognition data or, in normal operation, to connect the display to the output of the electronic equipment, to display data pertinent to the operation of the electronic equipment, for example the frequency of a tuned station. Two additional memories (5, 6) store, respectively, a predetermined code word and, upon entry from the data entry arrangement, the same code word. Unless the two code words agree,the recall switch (2) is changed to display only the personal recognition data, for example the vehicle registration.

Abstract: To retain an accessory apparatus including a tape unit, such as a tape deck forming part of an automobile radio, in a vehicle, such as a car or a boat, a dummy cassette (17) is provided, having an externally visible lock (18) which operates a locking bolt (23) which, upon lock operation, deflects from an aligned position with the dummy cassette through a window in the accessory or tape deck housing and through a holding frame (11) or holding strap (30) secured in the vehicle. The windows (27, 27', 27") in the dummy cassette, the accessory apparatus including the tape deck and the frame or strap in the vehicle are in alignment so that the bolt can be passed therethrough, thus preventing removal of the accessory apparatus from the vehicle. Preferably, the lock is so placed that it is visible, so that it will be immediately apparent that the accessory apparatus is locked against removal.

Abstract: For compensation of the effects of multi-path reception, a cascade distortion corrector composed of distortion corrector blocks successively connected in series is provided for a digital FM demodulator that needs non-recursive filtering. Each distortion corrector block produces an increase of the phase rotation and of the propagation time as well as a reduction of the reflection factor of the input signal. The cascade distortion corrector leads to a significant reduction of the hardware expense compared to the previously used transversal type filter structures. Sufficient compensation of the multi-path reception effects can be obtained by connecting five or six distortion corrector blocks one after the other.

Abstract: The multi-channel amplifier is placed on a common substrate to form a hybrid circuit network, for example a common silicon chip. A source of control voltage is provided connected in common to the base terminals of a pair of transistors, which have their emitters coupled together. The output is taken from the collector of one of the transistors via an emitter-follower transistor. The commonly connected emitters of the pair of transistors are connected through a current supply source forming a third transistor to a source of operating voltage.

Abstract: Pulses of constant pulse frequency but varying duty cycle are generated in a pulse generator which provides pulse trains or pulse sequences, as controlled by a pulse train or pulse length or sequence control unit coupled to the pulse generator and controlling the pulse generator to emit a train or sequence of pulses of similar pulse lengths, and further including a pulse length modulation control unit (12) coupled to the pulse generator and to the pulse train or sequence control unit, to control the length of the pulses of the individual pulse trains, the pulse lengths increasing in sequential pulse trains to provide an output signal of increasing intensity. The output from the pulse generator is filtered with respect to the base frequency, for example 800 Hz, and generated square wave pulses are converted into sawtooth wave pulses by a RC circuit to increase the dynamic range of output obtainable.

Abstract: Upon unauthorized removal of a car radio (2) from the chassis (C) of a car, a memory (5) which has a code stored therein is changed and inhibits operation of the car radio. The memory is retained in a predetermined memory state either by continuously receiving data inputs, for example from a potentiometer slider of a potentiometer (6), or data entered into an RAM energized only upon being properly connected in the vehicle. Alternatively, a user may enter a code, for example by operation of station selector buttons (4) of the car radio (2), and upon operating a set code switch (9), which code is destroyed upon removal of the radio, or upon failure to enter the correct code from time to time.

Abstract: When a transmitter sends information signals time multiplexed in a single channel over a coaxial cable to a receiver, the expense necessary for synchronizing the demultiplexing operations to the multiplexing operations at the transmitter and for supplying the current necessary to energize the receiver is reduced by impressing or interposing pulses on or into the multiplex signal at the transmitter for synchronization and current supply at the receiver. 12 V pulses are transmitted at low impedance either as frame pulses at the beginning or at the end of a signal pulse frame of the multiplex signal or supplementarily as clock pulses between successive signal samples in the multiplex signal.

Abstract: For elimination of pulse type interference in an FM receiver by intermittent blanking of the received signal while interfering pulses are present and substitution of a synthetic signal during the blanking intervals, the synthetic signal substituted during the blanking intervals is produced by interpolation using finite duration impulse response digital filters, instead of using the last undisturbed value of the received signal modified by integration of its last value of rate of change with respect to time. The determination of the blanking interval is optimized by reference to the maximum and minimum peak values of the output of an AM detector of the received signal and comparing an interference signal magnitude thus obtained with a threshold value of the interference signal, so as to define the blanking interval as the interval during which the interference signal exceeds the reference signal value.

Abstract: A transistor with its collector connected to a point near the screen grid in the resistor network which feeds voltage from the high voltage rectifier of a picture tube to the screen grid electrode and its emitter connected to ground has two control circuits connected to its base electrode. The first control circuit (56) is a threshold circuit responsive to a voltage proportional to the beam current of the picture tube for making the control transistor provide a short circuit between the picture tube screen grid and ground, and thereby preventing a burnout when there is persistent excessive beam current. The second control circuit (58) acts on the base electrode of the control transistor to set the screen grid voltage of the picture tube at a desired value in normal operation, for example in accordance with the pulse width of a train of pulses of settable pulse width.

Abstract: The tape of a video cassette providing oblique recording tracks of a longitudinal sound track for relatively narrow-band sound and a control track for vertical scan frequency synchronizing signals, instead of being usable alternately either for recording stereo and other wide-band sound on the oblique tracks and for recording television signals with sound either on the oblique tracks or on the longitudinal sound track, can be used for noninterfering superposed recording of sound on the oblique tracks using the usual FM sound signal carriers and a full television signal with the related sound on the longitudinal track. This is possible because by first recording the sound program on the oblique tracks, a greater depth of penetration of magnetization of the magnetic tape is produced than takes place with the recording of video signals.

Abstract: To permit transmission of traffic information by amplitude modulation in the medium wave band without disturbing audio signals being broadcast, a stereo pilot tone of frequency f.sub.pt below audible range is generated, as well as first and second sinusoidal signals of f.sub.1 =m.sub.1 /n.multidot.f.sub.pt and f.sub.2 =m.sub.2 /n.multidot.f.sub.pt, in which m.sub.1, m.sub.2, and n are different integers. The carrier is modulated by the stereo pilot tone and the first and second sinusoidal signals in such a manner that the phases thereof are different and further, when added, they do not essentially exceed the amplitude of the stereo pilot tone.

Abstract: To actuate an alarm in an automotive vehicle, already present therein, upon theft of a car radio or the like, an electrical switch is formed by a leaf spring (27) secured to a reception frame (11) installed in the vehicle, and insulated therefrom. The leaf spring (24, 24') has a free contact terminal end (27, 27') which, in one embodiment (FIGS. 2, 3), is insulated from contacting the metallic frame when the radio housing (10, 15) is properly secured in the frame by engagement of springy interlock abutments (18) in reception windows (21) in the frame. When properly secured, the free ends (27) of the springs engage a contacting metallic surface (28) on the housing (15) of the radio; upon removal of the housing, the end (27) of the leaf spring (24) rides on an insulated strip and, upon total removal, remains free, so that the switch changes state, thus actuating the alarm; in accordance with another embodiment (FIGS.

Abstract: Even though television signals are transmitted as analog signals over cable from the transmitter to the receivers of customers of the cable system, programs for which charges to the customers are payable are scrambled at the transmitter and unscrambled at the receiver on a digital basis, requiring digital-to-analog and analog-to-digital conversion both at the transmitter and at the receiver. In some cases there is such conversion at the receivers already for normal reception processing. By the provision of digital scrambling and unscrambling, it is possible to use a digital key which is subject to variation by a random signal generator, this key being transmitted during a one-line period that forms part of the vertical blanking interval. The unscrambling circuit has a built-in microprocessor so that its mode of operation corresponding to that of the control circuit at the transmitter is not readily detectible.

Abstract: Sixteen bit messages for selectively controlling receivers either to switch on an apparatus or to switch that apparatus off are transmitted on a format in which sixteen zeros are first transmitted, then a Willard sequence, then a control command, and then sixteen ones. The control command contains, in order of transmission, seven check bits, a control bit, seven address bits and a parity bit. The check bits are obtained by Nordstrom-Robinson coding from the eight data bits which consist of the seven address bits and a control bit, with cyclical rotation of the address bits but non-cyclical treatment of the control bit for deriving the seven check bits, with the result that, because the check bits and the control bit are received first, only three eight bit registers, each used twice first with the check bits as content and then with the address bits and the parity bit as content, are necessary for decoding at the receivers.

Abstract: A microphone picks up a signal in response to both the acoustic output of the speaker and the ambient noise at the loudspeaker location, for example, in an automobile. The microphone output signal and the signal which is to be provided to the loudspeaker with variable amplification are each subjected to envelope detection. The two envelope curve signals are compared to produce a signal representative of their similarity, the similarity being high when ambient noise is low or absent. The similarity signal is then processed with reference to a reference voltage which varies with the setting of the manual volume control of the amplifier interposed ahead of the loudspeaker. That amplifier has an automatic volume control input to which a control signal generated in response to the envelope similarity signal is applied to raise the amplification and the loudspeaker output level when ambient noise, detected by the similarity of the envelope signals, is present or increases.

Abstract: To provide for easy identification of the location of pushbuttons or other similar operating elements of an automobile radio, even in the dark, light guides which provide for function indication and positioned above the respective pushbuttons extend laterally beyond the respective pushbuttons, and the front surface of the panel is formed with a recessed surface having an inclined portion (23), in light transmitting location to an auxiliary light emitting surface (21) shining, from the light guides, downwardly on the inclined portion (23) to provide for lateral illumination of the push buttons which, then, will appear as shadows between the light emitted from the auxiliary light surfaces.

Abstract: FM transmission system in which, besides program content, an auxiliary carrier of, for example 57 kHz, is radiated, which auxiliary carrier is modulated by an announcement recognition (AR) signal and by a region or radio-station recognition (RR) signal, the AR and RR signals being low-frequency, AM modulations on the auxiliary carrier. To enhance recognition of an AR signal, e.g. between 142 and 170 Hz, is enhanced, in spite of reception difficulties, for example due to multi-path reception and the like, by decreasing the modulation of the 57 kHz subcarrier by the RR signal to 30% or less, while the AR signal is modulating the subcarrier, so that the AR modulation may extend to 60 and even 90% modulation. Multiple AR frequencies can be used, for example to characterize different announcements, e.g. in different languages, or of different characteristics, such as traffic, news, sports, or others, recognition of the AR signal in the receiver permitting switch-over from other reproduced programs, e.g.

Abstract: The projecting leads of electrical components can be automatically aligned by placing the component in a holder (12) with the leads (15) depending therefrom, sliding each lead into a tapered central groove (21) of a rotating alignment body (18), and withdrawing the lead once it has been re-oriented along a desired alignment axis (17). The holder (12) is reciprocated to and from the rotating bodies (18) along spring-loaded guide rods (13) riding in bores (10). A motor (5) drives the bodies (18) by means of pulleys (9, 19) and belts (20).

Abstract: To insure that a tape which is newly inserted into a reversing-type cassette tape transport mechanism will always operate in a first predetermined or priority direction, a direction priority switch (S3) is coupled to the tape cassette receiver (32, 34) to sense introduction of a tape into the receiver. The priority switch is coupled to a logic network which controls change-over of operation of a tape transport system (20, M) if the tape transport system, upon introduction of a tape, was operating counter the priority direction, but leaving unaffected the operation of the tape transport system if it was already in the priority direction. A suitable logic network comprises an AND-gate with a dynamic input, or one with a static input and a buffer memory which is reset upon termination of tape operation. If the tape is merely moved between a transducing position and a park or pause position, no change in direction of tape transport will result.

Abstract: Intermediate frequency FM signals are converted to digital form and the digital words of successive samples are clocked into a three place shift register. The sum of the values in the first and third stages of the register is divided by the value in the middle stage and the quotient values are then averaged by groups or as a moving average to provide the demodulated signal. Errors in the operation of the divider circuit can be avoided by detecting null values of the content of the middle cell of the shift register to suppress erroneous quotients, or else the values from which the quotients are formed are both squared before dividing. In the latter case the dc component can be eliminated from the output by subtracting a constant.