Abstract: An illuminating device for a portable radio apparatus of the present invention is capable of selectively turning on or turning off illumination in accordance with the environment around the apparatus, particularly lightness. This, coupled with the fact that the illuminating device can suitably adjust even an illumination, saves power to a considerable degree. Moreover, when the illuminating device includes light sensing means, it causes control means to automatically turn on or turn off illumination and adjusts an illumination in accordance with lightness around the apparatus. Therefore, even when the user of the apparatus forgets to switch the ON/OFF state of illumination, power consumption of the apparatus can be reduced as far as possible.

Abstract: A portable radio telephone or transceiver in which power source control is effected to prevent cases in which the telephone cannot be used due to lack of battery charge, and is made up of: a voltage detector 1 that detects the voltage of a battery 2 and outputs battery voltage information 11; memory 5 that stores voltage 51, which is a voltage at which the remaining charge of a battery is nearly exhausted, and voltage 521 higher than voltage 51, to enable the battery to operate the radio transceiver for at least one calling operation; key input detector 4 that detects the key input and outputs key input information 41; processor 3 which compares voltage 52 with battery voltage information 11 and outputs switch control signal 31 which operates to disconnect the battery from the main circuit when voltage information 11 is less than voltage 52; and switch 8 that disconnects the battery from main circuit 7 in accordance with switch control signal 31.

Abstract: Voltage setting information designating a battery voltage for initiating alarming and alarm setting information designating a method for outputting the alarm are input from a keying section and variably stored in a memory. A computing section compares battery voltage information in a battery detected by a battery voltage detecting section with the voltage setting information and, when the voltage in the battery voltage information is lower than the voltage in the voltage setting information, outputs an alarm sound signal or a call incoming lamp signal based on the alarm setting information to give the alarm to a user by sounding the alarm using a sound source or by emitting light using a call incoming lamp. This construction enables the residual capacity of the battery, at which alarming is initiated, and a method for giving the alarm to be varied as desired by a user.

Abstract: In a charging apparatus, a constant current circuit has a plurality of output terminals for supplying charging current with a plurality of current values, respectively. A plurality of contact pads connected to the output terminals of the constant current circuit. A conductive elastic lead has one of ends which slides in response to installation of a secondary battery in the case to contact one of the plurality of contact pads. Thus, a portion of the conductive elastic lead is connected to the secondary battery to supply the charging current from the constant current circuit to the secondary battery via the contacting one of the plurality of contact pads.