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Topic: Arduino as tachometer (Read 448 times) previous topic - next topic

Tawmeh

i believe you could put a piezo in with very little/no issue.

Paul_KD7HB

i believe you could put a piezo in with very little/no issue.
This afternoon I took a bit of time to Google "piezo tachometer" and found several commercial units available. So the concept is not new and readily accomplished.

Your next step, if you decode to go there, is to make a bracket or mount that is waterproof and heat proof and be able to attach to the exhaust system. You are lucky in that the engine has just one cylinder and is 4 cycle, so 2 revs per exhaust pulse.

Paul

cattledog

Quote
This afternoon I took a bit of time to Google "piezo tachometer" and found several commercial units available. So the concept is not new and readily accomplished.
As I understand the "piezo tachometers" they are based on the fuel injection pressure and not the exhaust.

From post 13
Quote
no high pressure tube to injectors.
Maybe the OP will be able to adapt the concept to exhaust pressure.

I've also seen reverence to an "acoustic tachometer" which is a phone app for deriving engine speed from the sounds.
 
https://play.google.com/store/apps/details?id=com.javiery.rpmgauge&hl=en

I am still very unclear why there is no access to a rotating piece of the engine. I'd consider drilling a hole through the flywheel bell housing.

How do the tachometers which the vendor sells for the high prices work? What signal do they use for rpm.

Paul_KD7HB

As I understand the "piezo tachometers" they are based on the fuel injection pressure and not the exhaust.

From post 13
Maybe the OP will be able to adapt the concept to exhaust pressure.

I've also seen reverence to an "acoustic tachometer" which is a phone app for deriving engine speed from the sounds.
 
https://play.google.com/store/apps/details?id=com.javiery.rpmgauge&hl=en

I am still very unclear why there is no access to a rotating piece of the engine. I'd consider drilling a hole through the flywheel bell housing.

How do the tachometers which the vendor sells for the high prices work? What signal do they use for rpm.
SEveral of my Google hits show either one of the pressure pipes going to an injector may be used or the exhaust impulse may be used with their equipment. All they are looking for is the shock impulse in the metal.

Should be and easy programming job. The difficulty will be in the mounting. Diesel exhausts are rather cool compared to gasoline engines.

Paul

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