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<div class="moz-cite-prefix">Pete,</div>
<div class="moz-cite-prefix">For most cooling fans the 3 wires are:
red = positive, black = negative, white = ground.</div>
<div class="moz-cite-prefix">A fan can create a lot of EMF, and the
extra ground is to suppress the noise reaching the circuit board.</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">However, on other fans: red = power,
black = ground, white = pulse control for PWM speed control.</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Either way, connecting red & black
for full power should do the trick unless you want to wire up a
555 PWM controller with a small pot to control the pulse width.
(ready-made circuit on Amazon: $7.50,
<a class="moz-txt-link-freetext" href="https://www.amazon.com/gp/product/B00QGMESHM/ref=as_li_ss_tl">https://www.amazon.com/gp/product/B00QGMESHM/ref=as_li_ss_tl</a> )<br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">Check out this blog on the subject:
"About PC Fans" <a class="moz-txt-link-freetext" href="https://www.rollitup.org/t/about-pc-fans.385722/">https://www.rollitup.org/t/about-pc-fans.385722/</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">or this one: "How to Create a
Three-Speed Fan Control without Spending a Dime"
<a class="moz-txt-link-freetext" href="https://www.hardwaresecrets.com/how-to-create-a-three-speed-fan-control-without-spending-a-dime/">https://www.hardwaresecrets.com/how-to-create-a-three-speed-fan-control-without-spending-a-dime/</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">or this video: "How to Power a Computer
Fan" <a class="moz-txt-link-freetext" href="https://www.youtube.com/watch?v=1UgoiEsoMzU">https://www.youtube.com/watch?v=1UgoiEsoMzU</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">finally this article: "PWM 3-Wires Fan
Controller with RPM feedback (Pulse Stretching Method)"
<a class="moz-txt-link-freetext" href="http://pcbheaven.com/circuitpages/PWM_3_Wires_Fan_Controller_with_RPM_feedback/">http://pcbheaven.com/circuitpages/PWM_3_Wires_Fan_Controller_with_RPM_feedback/</a></div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">- sgh<br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">On 2/2/21 1:15 PM, Pete Soper via
TriEmbed wrote:<br>
</div>
<blockquote type="cite"
cite="mid:10d349cf-4328-eea9-1bd2-051f4c7842da@soper.us">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<p>I pulled a fan/heatpipe assembly out of a laptop to have for
future experiments and wonder what sort of control I need for
it's three wire motor connection? Here's the label on the
outside. The DC resistance between any two pins with any
polarity is much higher than I would have expected: thousands of
ohms. <br>
</p>
Thanks,<br>
Pete<br>
<p><img src="cid:part1.D2DDAA89.95E198B0@gmail.com" alt=""
class=""></p>
<br>
</blockquote>
<p><br>
</p>
<pre class="moz-signature" cols="80">--
Scott G. Hall
Raleigh, NC, USA
<a class="moz-txt-link-abbreviated" href="mailto:ScottGHall1@GMail.Com">ScottGHall1@GMail.Com</a>
<font color="#006600"><i>Although kindness is rarely a job, no matter what you do it's always an option._</i></font></pre>
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