![Tooms on Twitter: "Today's mini project, fake PC fan tach signal to silent old servers alert monitoring in BIOS. Now it thinks the fan is running happy at 1500rpm, 555 timer chip Tooms on Twitter: "Today's mini project, fake PC fan tach signal to silent old servers alert monitoring in BIOS. Now it thinks the fan is running happy at 1500rpm, 555 timer chip](https://pbs.twimg.com/media/DbP2BUdXcAAF6vx.jpg)
Tooms on Twitter: "Today's mini project, fake PC fan tach signal to silent old servers alert monitoring in BIOS. Now it thinks the fan is running happy at 1500rpm, 555 timer chip
![frequency - Read out tachometer from PC fan when manually turning the blades ( driven shaft ) - Electrical Engineering Stack Exchange frequency - Read out tachometer from PC fan when manually turning the blades ( driven shaft ) - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/tuW59.jpg)
frequency - Read out tachometer from PC fan when manually turning the blades ( driven shaft ) - Electrical Engineering Stack Exchange
![sensor - 3 Wire Fan Tach, why using only one wire gives a signal? - Electrical Engineering Stack Exchange sensor - 3 Wire Fan Tach, why using only one wire gives a signal? - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/eDGIb.png)