| 摘要 |
PURPOSE:To reduce the drop of a battery voltage in a call at low temperature, and to normally and stably operate the receiver by detecting a temperature of the receiver and decreasing a driving current of a loudspeaker at the time of low temperature, in the radio selective calling receiver having the loudspeaker as an informing means. CONSTITUTION:A radio signal is amplified by a radio part l02, and thereafter, converted to a digital, signal which a decoder 104 of the next stage can read, by a waveform shaping circuit 103. In the decoder 104, a reference clock is formed by a crystal resonator 105, and when the own call number written in an exclusive memory 106 in advance and the received call number coincide with each other, in order to inform a carrier of a fact that there is a call, a call signal Sa is sent out to an amplifying part 107 and a loudspeaker 108 is driven. To the decoder 104 and the amplifying part 107, a function of a driving current control circuit for converting a driving current of the loudspeaker 108 by an output of a temperature detecting circuit 111 is given, and the driving current of the loudspeaker 108 is varied by the output of the temperature detecting circuit 111 so that the lower a temperature of the receiver is, the smaller the driving current of the loudspeaker 108 becomes. |
