There are a number of methods, but to find the easiest one, a little more needs to be known about the ignition system of the engine. If you want it to work on just about any motor and be portable, then the clamp on style current pickup from an inexpensive timing light could be made to work. If you can get to the primary side of the ignition coil easily, then just count the 12 volt pulses and divide appropriately. If it's a magneto ignition, the inductive clamp is the only low voltage method. Don't forget that you have twice as many revolutions/min as you have sparks/min to a given cylinder.
Brent DeWitt -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Lucamax Sent: Sunday, February 15, 2004 7:05 AM To: Info-LabVIEW Mailing List Subject: 4 stroke engine Rpm sensor Hi all, I need to acquire the RPM of a 4 stroke engine. Either using a digital input or an analog input of my acquisition board. Some digital tachometers <http://www.gpt.it/power_rpm%20eng.htm>use as sensor just an electric cable with a clip connected to the spark plug wire. Any idea how it can be done in such way ? Thanks !
