摘要 |
<p>A control circuit comprises a buzzer and an AC/DC buzzer/load control means having: a main current stream coupled to the load, and a current source connected in series with the main current stream of the AC/DC buzzer/load control means. The current source has only one combined input for simultaneously controlling the AC/DC power to the load for buzzer volume and pitch control. Such a control circuit can easily be implemented in an IC such as a telephone IC.</p> |