| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a device without requiring the increase of the number of batteries by installing a secondary battery supply power to a radio transmission section and having a low impedance output and a primary battery charging power consumed at the time of transmission of the secondary battery. SOLUTION: An output from a primary battery 1 is connected to a step-up circuit 2, and stepped up to a voltage slightly higher than the voltage of a secondary battery 4 and applied to a switch 3 and a control section 5. When transmission is conducted, a transmission control signal 101 reaches an on-output and a transmission section 6 is operated, but the transmission section 6 is detached from the primary battery 1 because a chargeing control signal 102 reaches an off-output and the switch 3 is turned off, and the secondary battery 4 is used as a power supply and all power required at the time of transmission is supplied from the secondary battery 4. When the transmission control signal 101 of the control section 5 reaches the off-output and the transmission section 6 stops transmission, the charging control signal 102 reaches the on-output, and the stepped-up output voltage of the primary battery 1 is applied to the secondary battery and the secondary battery is charged. Accordingly, a device can be miniaturized without requiring the increase of the number of the batteries. |
