Matsushita Electric Industrial Co., Ltd.

Kouichi Kunitomo

Jun Sato

Takehiko Sato

Takahiro Hayashi

Shinichi Fujita

Mikio Hanabusa

A portable telephone comprises a charging circuit for charging a battery with an external power supply, a voltage detector for detecting a terminal voltage of the battery, a memory storing charge-restart threshold voltages and charge-restart times corresponding to various use-states of the telephone, and a controller for monitoring the use-state of the telephone, selecting the optimum one of the charge-restart threshold voltage and optimum one of the charge-restart times in accordance with the use-state of the telephone, and carrying out timing control to recharge the battery.

Portable telephone with built-in charger

A charging control circuit is disclosed which comprises: a 1st connector (17) receiving an input supply power (34); a 2nd connector (30) for supplying a charging supply power (35) to charge either of a 1st (Ni-Cd) or 2nd (Lithium ion) battery (33a, 33b) and receiving a discharging supply power (36) from the battery; a kind detection portion (15) for detecting which of the 1st and 2nd kind of battery is to be charged; a voltage detection circuit for detecting an emf of the battery to be charged; a current detection circuit for detecting a charging current to the battery to be charged; a REF signal generation portion (15) for generating a REF signal (38) in accordance with outputs from the kind detection portion, the current detection circuit, and the voltage detection circuit; a difference providing portion (111) for providing a difference between the REF signal and the detected emf; and a charging supply power generation circuit for generating the charging supply power from the input supply power according to the output of the difference providing portion (111). The Ni-Cd battery is charged by a constant current and the lithium ion battery, by a constant current and a constant voltage (4.1 V). Completion of charging is detected by a drop of emf of Ni-Cd and decrease in the charging current to Lithium ion battery.

Charging control circuit

A transmitting power control unit which generates and transmits a wideband transmission signal with a power level which does not differ by frequency. This transmitting power control unit includes means for generating voltage corresponding to a frequency of a transmission signal. The power of the transmission signal is controlled by added the voltage which is obtained by adding the generated voltage to a fixed voltage according to power control information. The power-controlled transmission signal is transmitted from an antenna with a frequency band thereof limited by a filter.

Transmitting power control unit having a constant output level

It is an object of the invention to control a bias current of each of the amplifying elements of an exciting section and a power amplifying section in accordance with a magnitude of an amplitude control signal. A value of a control signal which is supplied to a control signal input terminal is adjusted in accordance with a magnitude of a signal to be generated which is given by an amplitude control signal. Bias currents of transistors are adjusted by the control signal. Thus, an output voltage of the exciting section is variably controlled by a control signal. Further, gate voltages of transistors are adjusted by a voltage which is applied to a gate voltage terminal. Electric power, which can be output from the power amplifying section, is variably controlled.

Transmission output amplifier

In a vehicle-mounted charging apparatus for a portable telephone set comprising a portable telephone set and a vehicle-mounted charger in combination, a constant voltage charging control microcomputer in the charger receives information on a voltage of a battery pack and information on the on/off state of power supply to the telephone set and performs charging control so that rapid charging is performed within an appropriate charging temperature range, while trickle charging is performed outside the appropriate charging temperature range, on the basis of information on the temperatures in the battery pack detected by a temperature sensor 15 provided in the battery pack. When trickle charging should be performed, a charging-special microcomputer is switched to a trickle charging mode. In this state, when the telephone set is supplied with power from the battery pack and the voltage of the battery pack is low, a constant voltage source in the charger is operated to supply power to the telephone set. When the charging-special microcomputer is switched to the rapid charging mode, the operation of the constant voltage source is stopped. Thus, the vehicle-mounted charging apparatus for a portable telephone set constructed as above is adapted to any condition of use in a vehicle-mounted state.

Vehicle-mounted charging apparatus for portable telephone sets

Disclosed is a transmission power amplifier device comprising a GaAs power amplifier using a GaAs FET as its amplifier element. In order to compensate the non-linearity of the frequency characteristic of the transmission power amplification efficiency of the GaAs power amplifier with respect to individual amplified signal transmission channels, gate voltage information for each of the channels is stored beforehand in a memory, and a gate voltage obtained by adding a fixed voltage to an analog voltage generated on the basis of the gate voltage information read out from the memory is applied to the gate of the GaAs FET so as to flatten the frequency characteristic of the transmission power amplification efficiency.

Transmission power amplifier device

A modulation sensitivity correction circuit in which a phase-locked loop includes a voltage-controlled oscillator (VCO) and a phase detector. When an audio signal is applied to the VCO through an electronic volume control so as to be modulated, control for the electronic volume control is effected by using a control voltage obtained by applying an output of the phase detector to a conversion circuit having a characteristic which is the reverse of the modulation sensitivity characteristic of the VCO, so that the modulation sensitivity can be kept constant over a wide band.

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Yokohama, Japan

Kouichi Kunitomo