Abstract: A portable telephone terminal where power is supplied from a series power supply when the portable telephone terminal is in a wait state or a state where processors and the like are not in full operation. When the processors and the like are in a busy operating condition, power is supplied from a DC/DC converter. While the series power supply supplies power, operation of the DC/DC converter is stopped.

Abstract: In a wait state of a portable telephone terminal or a state in which processors and the like are not in full operation, power is supplied from a series power supply. When the processors and the like are in a busy operating condition, power is supplied from a DC/DC converter While the series power supply supplies power, operation of the DC/DC converter is stopped.

Abstract: A magneto-optical disc recording and/or reproducing apparatus having an external magnetic field generating means for supplying an external magnetic field to a magneto-optical disc, a spacer sheet disposed relative to the magneto-optical disc at its surface side opposing to the external magnetic field generating means and a moving means for moving the external magnetic field generating means in the direction in which the external magnetic field generating means is isolated from and brought in contact with the magneto-optical disc, in which the moving means moves the external magnetic field generating means to the position at which the external magnetic field generating means comes in contact with the magneto-optical disc via the spacer sheet when an information signal is recorded on the magneto-optical disc, whereas the moving means moves the external magnetic field generating means to the position distant from the magneto-optical disc when the information signal recorded on the magneto-optical disc is reprodu

Abstract: A spread spectrum signal receiving apparatus comprising: a radio frequency processing circuit for converting a spread spectrum signal into an intermediate frequency signal; a binary encoder for encoding the intermediate frequency signal; a pseudo-random noise code generator; a code driver for controlling the phase and the chip speed of the output of the code generator; a first multiplier for multiplying the binary signal by the output of the code generator; a numerical controlled oscillator for outputting first and second carrier signals; second and third multipliers for multiplying the output signal of the first multiplier respectively by the first and second carrier signals; first and second low-pass filters supplied with the output signals of the second and third multipliers respectively; and a microcomputer having functions to produce signals for controlling the numerical controlled oscillator, and functions to produce signals for controlling the code driver.

Abstract: A receiver has a first input circuit and a first amplifier connected to a first rectifier circuit and has a second input circuit and a second amplifier connected to a second rectifier circuit. The first and second rectifier circuits produce first and second direct current signals, and the first and second rectifier circuits are connected to a meter drive circuit which produces a direct current signal in response to the first or second direct current signal so that the direct current signal from the meter drive circuit actuates a meter to indicate the input level of either the first input circuit or second input circuit.

Abstract: A frequency converter of the type having a local oscillating stage for producing a local oscillating signal and a double-balanced type mixing stage provided with a first pair of inputs for receiving a signal to be frequency converted and a second pair of inputs for receiving the local oscillating signal. The output of the mixing stage can be connected through a tuned circuit so as to frequency convert the input signal to an intermediate frequency (IF) signal. The local oscillating stage includes a first pair of differentially-connected transistors, the collector electrode of one being connected to a resonant circuit and, additionally, through an RC positive feedback circuit to the base electrode of the other transistor. The double-balanced type mixing stage includes a second pair of differentially-connected transistors, one of which being connected in cascade with a first differential amplifier and the other of which being connected in cascade with a second differential amplifier.

Abstract: A receiver with an automatic gain control system is disclosed in which the signal path between the output coil of an antenna tuning coil and a first stage of a circuit supplied with a received signal from the antenna tuning coil is connected in parallel with a plurality of variable impedance elements, resistors are connected in series between at least the plurality of variable impedance elements, and an automatic gain control signal is supplied to the plurality of variable impedance elements to thereby perform an automatic gain control.

Abstract: A magneto-optical disc recording and/or reproducing apparatus having an external magnetic field generating means for supplying an external magnetic field to a magneto-optical disc, a spacer sheet disposed relative to the magneto-optical disc at its surface side opposing to the external magnetic field generating means and a moving means for moving the external magnetic field generating means in the direction in which the external magnetic field generating means is isolated from and brought in contact with the magneto-optical disc, in which the moving means moves the external magnetic field generating means to the position at which the external magnetic field generating means comes in contact with the magneto-optical disc via the spacer sheet when an information signal is recorded on the magneto-optical disc, whereas the moving means moves the external magnetic field generating means to the position distant from the magneto-optical disc when the information signal recorded on the magneto-optical disc is reprodu