Editing Computer fan control (section)

==== Diodes ====
A [[diode]] in series with the fan will reduce the voltage being output to the fan. A [[silicon diode]] provides a relatively constant voltage drop of about 0.7&nbsp;V per diode; data sheets for a specific diode specify its voltage drop, for example the 1N4001 silicon diode's voltage drop varies from approximately 0.7 to 0.9&nbsp;V as the current varies from 0.01 to 1&nbsp;A.<ref>{{Cite web |url=http://www.diodes.com/datasheets/ds28002.pdf |title=Archived copy |access-date=2015-02-26 |archive-date=2012-09-04 |archive-url=https://web.archive.org/web/20120904002853/http://www.diodes.com/datasheets/ds28002.pdf |url-status=dead }}</ref> The [[Electric power|power]] rating should be noted and some diodes may require cooling to operate at their rated current. The voltage drop across the diode will fall with temperature, causing the fan to speed up.

Like other series regulators, the diode will dissipate power equal to its voltage drop times the current passing through it.