Abstract: In a spectrum analyzer, an input signal is divided into a plurality of frequency bands, the signal level of each of the divided frequency bands is detected, and the signal levels of frequency bands situated between the divided frequency bands are calculated, for example, by arithmetic operating circuits, from the detected signal levels of the divided frequency bands adjacent thereto, whereupon the detected signal levels of the divided frequency bands and the calculated signal levels of the frequency bands between the divided frequency bands are all displayed, for example, as respective bar graphs, so that the frequency characteristic of the input signal can be readily observed.

Abstract: The present invention relates to a scrambling apparatus and particularly to a scrambling apparatus in which a scrambling signal is inserted into a main signal in a predetermined period (period of duration during which the main signal is not damaged) of the main signal which makes a dummy signal.According to an embodiment of the present invention, there is provided a scrambling apparatus which comprises a detecting circuit (36) for detecting that the level of the above main signal becomes lower than a predetermined value and an adding circuit (25) for adding the above main signal and the scrambling signal whereby the supply of the above scrambling signal to the adding circuit (25) is stopped by the output from the detecting circuit (36) to prevent the scrambled signal from being leaked.The scrambling apparatus of the invention can be applied to an interphone and the like.

Abstract: A power supply circuit for supplying stabilized positive and negative DC voltages of opposite polarity but equal magnitude requires only a single voltage source that supplies a first DC voltage, and a polarity converting circuit connected to the voltage source provides a second DC voltage equal in magnitude but opposite in polarity to the first DC voltage. First and second voltage stabilizing circuits are connected to the voltage source and the polarity converting circuit, respectively, to provide between respective output terminals and a common ground line the equal level but opposite polarity voltages. Voltage stabilization is provided in the stabilizing circuits by the use of Zener diode circuits to provide biasing to control the collector-emitter paths of respective transistors, and polarity conversion is accomplished by a switching transistor controlled by a pulse-width modulation signal generator having its input derived from a level comparison circuit.

Abstract: A printed circuit board substrate is mounted with electric circuit components to form an electric circuit thereon. The printed circuit board is provided with a land without a piercing hole for electrical connection with an electrode of a chip-shaped leadless element, and a land with an aperture for the insertion of the lead wire of a component or element with a lead, and further a pilot pattern for leading melted solder in spite of the presence of evaporated solder flux gas or air during a solder dipping operation. The pilot pattern may comprise a conductive pattern connecting the land for the leadless element and the land for the element with lead. At least elimination of the solder resist layer on a portion of the conductive pattern to form the pilot pattern.

Abstract: Electrical circuit apparatus comprising a mother board having pattern of conductive leads on a surface thereof and including at least one opening therein of predetermined size and shape into which is fitted a daughter board which is structurally distinct from the mother board, the mother and daughter boards being of substantially the same thickness. Electrical circuit components are mounted on the composite board which is formed by the combination of the mother and daughter boards, these electrical circuit components having electrodes which are electrically connected to the pattern of conductive leads of the composite board. Preferably, both the mother and daughter boards are provided with patterns of conductive leads. The leads on the mother and daughter boards are interconnected, either directly or through circuit elements. Also disclosed is a process for manufacturing this composite board.

Abstract: A record player has a turntable, a drive means to turn the turntable, a position detecting means for detecting the rotational position of the turntable and a stopping means for stopping the turntable. The stopping means is operated by a detecting output from the position detecting means so as to stop the turntable at a predetermined position.

Abstract: A tantalum condenser includes a metallic electrode cap; a tantalum material fitted to the metallic electrode cap; a cylindrical metallic electrode facing to the metallic electrode cap; a tantalum lead projected from one end surface of the tantalum material; and a projection formed integrally with one end surface of the metallic electrode, and welded to the tantalum lead, wherein a part of the metallic electrode cap, the tantalum material, a part of the metallic electrode, the tantalum lead and the projection are molded with synthetic resin.

Abstract: A hybrid integrated circuit is manufactured byplacing chip-type circuit elements on predetermined portions of a template;preparing a printed circuit board having predetermined conductive patterns thereon and adhesive material at predetermined portions thereof;placing the printed circuit board on the template so as to bring the circuit elements into contact with the adhesive material;turning the template with the circuit board upside down and then transferring the circuit elements to the circuit board by removing the template from the circuit board;hardening the adhesive material to temporarily hold the circuit elements on the circuit board; andsoldering the circuit elements to conductive patterns formed on the circuit board, so as to electrically connect the circuit elements with the conductive patterns.

Abstract: In an electronic circuit arrangement mounted on a printed circuit board in which leadless circuit parts are attached to the printed circuit board with adhesive. A white paint is applied onto a region to which adhesive is applied, and an adhesive containing pigment contrastable to the white paint is applied onto the paint.

Abstract: A printed circuit board includes an insulating board; at least one pair of conductive patterns arranged on the insulating board and spaced from each other by a predetermined length; and a paint layer formed in the space between the conductive patterns within a predetermined range.

Abstract: A switching regulator includes an inrush current protective resistor and a starter circuit for a pulse width modulator consisting of a starting resistor and a capacitor. At initial starting mode, the inrush current protective resistor is connected to the starter circuit, and after starting both of the inrush current protective resistor and starting resistor are disconnected so as to reduce power dissipation or consumption thereby. At the same time, a DC voltage source for the pulse width modulator is derived from a rectified secondary voltage through the starting capacitor.

Abstract: In a record player having a tone arm support moved, as by a rotated screw or other feeding device, in a feeding path that is in parallel, spaced relation to a radius of the turntable so that a pickup stylus depending from the tone arm will move linearly along that radius in tracking the groove of a record disc on the turntable with the tone arm in a predetermined angular relationship to the feeding path, and in which any deviation of the speed of movement of the tone arm support by the feeding device relative to the speed of movement of the stylus by its engagement with the record groove is accompanied by angular displacement of the tone arm from the predetermined angular relationship to the feeding path; a periodic signal has an angular characteristic thereof, such as, the frequency or phase, varied in accordance with detected angular displacements or deviations of the tone arm from the predetermined angular relationship to the feeding path, a reference signal of constant frequency or phase is compared with

Abstract: In a record player, a turntable is rotatably mounted on a base, and a rotor structure, such as an annular magnet, is mounted on the turntable and cooperates with a stator aperture mounted on the base to cause the turntable to rotate. The annular magnet is preferably a rubber magnet formed by molding rubber mixed with a ferrite powder. For the sake of stability, the annular magnet is in close proximity to the circumference of the turntable. The stator aperture preferably includes bobbins on which stator coils are wound, and arcuate tongues, integral with the base, on which the bobbins are arranged and which form magnetic cores for the stator coils.

Abstract: A control circuit is disclosed for use in a switching-type regulator which includes a source of unregulated DC voltage, a switching circuit for interrupting the unregulated DC voltage to produce an AC voltage having a duty cycle which is a function of the operation of the switching circuit, a converter for converting the AC voltage to a regulated DC voltage, a controllable pulse generator for supplying pulses of controllable duration to the switching circuit so as to determine the duty cycle of the AC voltage, a feedback circuit responsive to variations in the regulated DC voltage for controlling the duration of the generated pulses to maintain the regulated DC voltage at a desired level, and disabling circuit for selectively limiting the operation of the pulse generator. The control circuit is used to reset the disabling circuit to an initial state and to change gradually the duration of the pulses which are generated by the pulse generator when the regulator first is turned ON.

Abstract: Apparatus for controlling an arm of a record player of the type having a base, a turntable upon which a record disc rotates, a pivot support extending upward from the base for supporting the arm and about which pivot support said arm pivots in a plane perpendicular to the surface of the record disc, and a transducer at one end of the arm for scanning the record disc. Pivotal movement of the arm is detected and a position signal is produced to represent the angular position of the arm. A detecting circuit detects when the position signal differs from a predetermined reference signal, this difference corresponding to an angular displacement of the arm, to produce a control signal. A drive device is coupled to the pivot support and is responsive to the control signal for driving the pivot support in a direction perpendicular to the surface of the record disc so as to reduce the angular displacement of the arm and thereby adjust the position signal until it is equal to the predetermined reference level.

Abstract: A current mirror circuit comprised of three transistor devices, each transistor device including an input terminal and first and second output terminals. Two of the devices have their input terminals connected together and one output terminal of each device is connected to a respective current output terminal. The other output terminal of each device is adapted to be supplied with an operating voltage. Each of the first and second transistor devices is formed of at least a pair of transistors connected in Darlington-type configuration. In one embodiment, these Darlington-connected transistors are of complementary types. The third transistor device has its input terminal coupled to one of the current output terminals and one of its output terminals coupled to the common-connected input terminals of the first and second transistor devices. The remaining output terminal of the third transistor device is coupled to a reference potential.

Abstract: A phase locked loop includes a variable frequency oscillator, a phase comparator for comparing the phase between an output signal derived from the variable frequency oscillator and a reference signal and for generating a control signal in response to the phase difference between the two signals for controlling the variable frequency oscillator, an indicator for indicating the phase difference between the signals, and a control circuit for varying the frequency of the variable frequency oscillator.

Abstract: A current control circuit for a muting circuit including a current mirror circuit formed of first and second transistor devices, one of which being operative to receive a controllable current and the other being operative to conduct a current whose value is determined by and changeable with the controllable current, such other transistor device being adapted to be connected to a load. A constant current generator generates a substantially constant current and is connected to a current-responsive circuit which, in turn, supplies the controllable current to the first-mentioned transistor device included in the current mirror circuit.

Abstract: A stereo demodulator system includes first and second differential amplifiers differentially responding to a first form of a stereo signal and at least a pair of differentially connected transistors serially connected to the output circuit of the first differential amplifier and responding to a second signal related to the first signal. A current mirror circuit is provided from the output circuit of the second differential amplifier to the pair of differentially connected transistors to produce a mixed output signal at the output terminal of the pair of transistors to separate the stereo signal into component signals. An offset current compensator is provided to avoid producing an offset current in the mixed output signal.

Abstract: A gain control circuit includes first and second variable impedance devices connected between signal input and signal output terminals. A first current source (or sink) is connected to the connection point of the impedance devices and second and third current sinks (or sources) are connected to the input and output terminals. The output signal is controlled by varying the currents of the first through third current sources (or sinks) in such a way that the current value of the first current source (or sink) equals the total current value of the second and third current sinks (or sources).