| 摘要 |
PROBLEM TO BE SOLVED: To provide an incoming call detector that operates for a long time without any external power supply and monitors a drive capability of a drive power supply and recognizes an incoming call to any of pluralities of kinds of portable radio telephone sets without the need of holding a receiver. SOLUTION: An antenna 1 selectively receives a carrier signal emitted by a portable telephone set or the like, a high frequency amplifier section 2 amplifies the signal, a binarized signal of the detection result is given to a timer section 4. The timer section 4 outputs pulses in a prescribed length. The timer section 4 does not detect a new incoming call for about 5 sec after the end of a preceding incoming call. A lamp drive section 5 receives the pulse and blinks LEDs 1-3 while the pulse is at a high level. A power supply section 6 provided with a battery E1 supplies power to each section and a solar battery E2 charges the battery E1. A power consumption control section 7 supplies power to a broad band amplifier Q1 intermittently. Furthermore, the lamp drive section 5 discriminates an electromotive force of the battery E1. |
