| 摘要 |
PURPOSE:To attain high output transmission for a short time by charging a capacitor supplying a drive power to an output amplifier stage via a constant voltage circuit by a power supply circuit and supplying a transmission signal to the output amplifier stage for a prescribed period only after the charging voltage rises to a prescribed voltage or over. CONSTITUTION:The capacitor 70 supplying drive power to a power amplifier 31 of the output amplifier stage 30 via a constant voltage circuit 75 is charged gradually by a DC-DC converter 53 of a power supply 50. When it is detected by a comparator 60 that the charging voltage Vc of the capacitor 70 rises a prescribed voltage Vref or over, a transmission data is supplied from a pre- stage circuit 10 for a prescribed period only to operate the power amplifier 31. When the transmission signal fed from the pre-stage circuit 10 is lost, the output amplifier stage 30 stops its operation to charge the capacitor 70 again and the transmission operation is repeated. |
