Pages: [1]   Go Down
Author Topic: Measure RPM with IR reciever.  (Read 703 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Sr. Member
Karma: 3
Posts: 444
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Can I measure RPM with an IR receiver and IR LED and simply put them on opposite sides of for instance a fan... Or put a white mark on something dark and reflect the IR back. I notice that most IR receivers say they are 38kHz, what does that mean? Does it not simply send a pulse when it receives IR light? I'm not looking to do anything specific here, I would just like to put together something simple like this.


Massachusetts, USA
Offline Offline
Tesla Member
Karma: 212
Posts: 8954
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

IR receivers are for remote controls as used for home AV equipment.  They expect a modulated IR signal at 38 kHz so they can filter that signal out of the background.

For a tachometer you need a raw IR phototransistor or photodiode  Here's an example using a PIC microprocessor that should connect to an Arduino just as well:

Send Bitcoin tips to: 1L3CTDoTgrXNA5WyF77uWqt4gUdye9mezN
Send Litecoin tips to : LVtpaq6JgJAZwvnVq3ftVeHafWkcpmuR1e

Pages: [1]   Go Up
Jump to: