PC Alarm fan RPM.

Hello:

With a PC fan with yellow tachometer cable I want to control the speed. For example, a fan runs at 12 V. The yellow cable is loose tachometer 5 V and may thereby directly connected to Arduino.

Having a 16x2 LCD displays revolutions want as the background. The main thing I want to do is, if detected after a time the tachometer or is 0 V. Arduino detects this and gives an alarm with a buzzer and LCD displays the ALARM message.

Also good to know which speed to the buzzer if zonar is very slow, depends on the RPM speed.

How is it done? (I refer to programming).

A greeting.

hardware ? tachometer datasheet ? schematic of circuit ?

Hi:

The basic scheme is this without LCD.

Something similar here.

Any data or information more?

A greeting.