Abstract: Class D audio amplifiers provide a dual benefit for battery-powered portable devices. They enhance battery life, and they produce much less power dissipation than do their linear cousins. Those features make the class D amplifier an ideal candidate for controlling speed and direction in small electric motors. Class D audio amplifiers provide a dual benefit for battery-powered portable devices. They enhance battery life, and they produce much less power dissipation than do their linear cousins. Those features make the class D amplifier an ideal candidate for controlling speed and direction in small electric motors. As shown in Figure 1, the standard application circuit for a class D audio amplifier (U1) requires only slight modifications. In place of the usual audio-signal input is a variable DC voltage generated by a potentiometer (R2). Resistor R1 biases the potentiometer to match the input range of U1. Full counter-clockwise rotation of the pot corresponds to maximum-speed reverse rotation of the motor. Mid-scale on the pot corresponds to motor off, and full clockwise rotation of the pot produces maximum-speed forward rotation in the motor. Figure 1. A class D audio amplifier (U1) helps implement this simple motor-speed controller. The characteristics of a given motor may allow you to eliminate the amplifier's output filter (L1, L2, C1, and C2). But, unless the control circuitry shown is located near the motor, you should include the filter to reduce EMI. A similar version of this article appeared in the May 1, 2003 issue of EDN magazine. 相关型号   APP 1951: Mar 25, 2003 MAX4295 单声道/立体声、2W、开关模式(D类)音频功率放大器 完整的数据资料 (PDF, 544kB) 免费样品 自动更新 需要自动接收最新发布的应用笔记吗？请订阅EE-Mail™ (English only)。 我们期待您的反馈！ 喜欢？不喜欢？有待改善？或为我们提供建议？请与我们联系 — 我们将根据您的意见或建议改善我们的工作。 网页评价或提供建议   下载，PDF格式 (25kB)  AN1951, AN 1951, APP1951, Appnote1951, Appnote 1951