https://knightli.com/tags/dc%E8%B0%83%E9%80%9F/ Recent content in DC调速 on KnightLi的博客 Hugo -- gohugo.io zh-cn Tue, 06 May 2025 00:00:00 +0000 https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/ Tue, 06 May 2025 00:00:00 +0000 https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/ <h2 id="接口定义">接口定义 </h2><ul> <li>插座 风扇插座, 2510错位3+1P 4P风扇散热针座<br> 4针，3针风扇均可插到这个插座上<br> <img src="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/1.png" width="361" height="489" srcset="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/1_hu_cb6598f08d81425a.png 480w, https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/1_hu_40bd393eea2784e5.png 1024w" loading="lazy" class="gallery-image" data-flex-grow="73" data-flex-basis="177px" ></li> <li>4针风扇插座 <br> <img src="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/2.png" width="347" height="597" srcset="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/2_hu_7b5cd10916131315.png 480w, https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/2_hu_bebeeeae615f720a.png 1024w" loading="lazy" class="gallery-image" data-flex-grow="58" data-flex-basis="139px" ></li> <li>3针风扇插座 <br> <img src="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/3.png" width="311" height="341" srcset="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/3_hu_7e75f7c9c82c93f7.png 480w, https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/3_hu_2f76c3b465e21cd.png 1024w" loading="lazy" class="gallery-image" data-flex-grow="91" data-flex-basis="218px" ></li> </ul> <h2 id="测速">测速 </h2><p>TACH, FG转速信号 通过这个针脚测速 散热风扇的FG信号是连续方波信号，反映风扇实时转速.<br> 一般无刷电机是4个磁级对数，FG信号的方波与磁级对有关。4个磁极对风扇，2个周期表示转了一圈，也可以理解为当计数器检测到2个高电平时，风扇转一圈，6个磁级对数，即为检测到3个周期表示风扇转一圈，即3个高电平。<br> 风扇转速单位一般是转数/每分钟, 所以对于4个磁极对风扇, 转速=FG频率<em>30, 对于6个磁极对风扇, 转速=FG频率</em>20</p> <h2 id="dc调速">DC调速 </h2><p>通过调整风扇供电的电压实现调速</p> <h2 id="pwm调速">PWM调速 </h2><h3 id="pwm信号占空比">PWM信号占空比 </h3><p><img src="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/4.png" width="1867" height="651" srcset="https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/4_hu_9abb7044887388d6.png 480w, https://knightli.com/2025/05/06/pwm%E8%B0%83%E9%80%9F-dc%E8%B0%83%E9%80%9F-%E9%A3%8E%E6%89%87-%E6%8E%A5%E5%8F%A3%E5%AE%9A%E4%B9%89/4_hu_da6b57b833752ee.png 1024w" loading="lazy" class="gallery-image" data-flex-grow="286" data-flex-basis="688px" ></p> <p>占空比D定义为脉冲持续时间（τ）与方波周期（T）的比值。</p> <p>PWM调速通过改变PWM引脚信号的占空比（Duty Cycle），即脉冲信号高电平的时间占整个周期的比例，来控制风扇的转速。例如：<br> 100% 占空比 → 风扇全速运转<br> 50% 占空比 → 风扇半速运行<br> 0% 占空比 → 风扇停止</p> <h3 id="pwm信号频率">PWM信号频率 </h3><p>PWM调速频率指的是PWM信号的开关频率，即单位时间内脉冲信号切换的次数，通常以赫兹（Hz）表示。例如，PWM调速频率为20kHz，表示PWM信号每秒钟切换20000次。</p> <p>常见的PWM风扇调速频率范围：<br> 低频：1kHz<del>5kHz（部分旧款风扇使用）<br> 标准频率：20kHz</del>30kHz（大部分高性能风扇使用）<br> 高频：&gt;30kHz（部分静音风扇或特殊用途风扇）</p> <h3 id="pwm信号幅值">PWM信号幅值 </h3><p>PWM的幅值是指高电平和低电平之间的电压差异。一般来说，常见的PWM幅值为3.3伏特（V）或5伏特（V），但具体要求取决于风扇的规格和设计。在选择宽值时，需要确保PWM信号能够被风扇正确理解和响应。可以参考风扇的规格书或制作制造商提供的技术资料，了解了使用风扇的PWM幅值要求。</p>