# Counter pulses of Pc fan with simulink

#### Avic

Joined Jun 4, 2008
4
Hi.
I need to do a pulse counter in simulink. These pulses will be acquired from a
fan tachometer with Dspace DS1102.
Anybody have an idea for build this counter? I tried with one builded with JK
flipflops but does not works well.

I need a reset as well because I will pass that pulses to RPM in a specific time.
(two pulses, one RPM).

Please, if somebody can give me an idea I will be very glad.

#### roddefig

Joined Apr 29, 2008
149
I'm assuming it's a discrete system. You can make one with a summation block and a discrete-time integrator. Just integrate over your pulse period, and assuming it's either a one or a zero you'll get the number of pulses at the output. See below.