| 摘要 |
PURPOSE:To obtain a specific transmission level from a battery which has a low rated output voltage by charging a capacitor in ultrasonic-wave transmission stand-by mode, and connecting the capacitor in series with a power source during transmission and impressing a voltage to a transmission part. CONSTITUTION:A transmission driving signal generated by a timing control circuit 1 switches a transistor Q1 connected in series with a transmitter A to drive the transmitter A. A transmission part power source 6 doubles and impresses the battery voltage to the transmitter A. This transmission part power source 6 has an electrolytic capacitor 24, which is charged in a ultrasonic-wave transmission stand-by mode and connected in series with the power source during the transmission to impress the battery voltage and the voltage across the capacitor to the transmitter A together. |
