| 摘要 |
PURPOSE:To subminiaturize a tuner part dedicated to an earphone by forming the tuner part and a speaker part having batteries independently, and driving both parts by a power source battery of the speaker part when both parts are connected together. CONSTITUTION:While a power switch 11 is on, the tuner part A is in operation. When the tuner part A is disconnected from the speaker part B, the switch 11 turns on and contacts 12 and 13 are broken. Therefore, the tuner part A is driven by the power source battery dedicated to the tuner part. Then, when the tuner part A and speaker part B are connected to a preamplifier 3, the contacts 12 and 13 are made and the switch 11 turns off mechanically at the same time. Therefore, the power supply from the power source battery 7 is cut off in this case and the tuner part A and speaker part B are both powered on by a power source battery 10. |
