| 摘要 |
<p>An electronic control unit is used to start or stop the turntable of a record player. It has no mechanical parts as it uses electrical signals from the cartridge and a push-button. The electronic unit (1) interfaces between the cartridge or stylus (2) and the components (5, 6, 7) of the turntable such as motor, amplifier. It has four modules (E1, E2, E3, E4). The first module (E1) extracts part of the signal from the cartridge (2). The second module (E2) compares the signal with a reference (4). If the signal is greater than a threshold then a time delay module (3) is excited. Another module (E4) is used to operate the components (5, 6, 7) of the turntable. The signal (2') from the cartridge is used to maintain operation of the turntable. The signal (3) from a switch is used to start the turntable.</p> |
