Manky Monkey Motors

Technical Section => Trike Tech => Topic started by: andyrennison on May 20, 2013, 08:03:48 PM



Title: Frequency Calcs - Sanity check please
Post by: andyrennison on May 20, 2013, 08:03:48 PM
Can someone please do me a sanity check on my figures?

Reliant engine, there are 2 sparks per single revolution of the engine, yes??

If so 3000 rpm = 3000 / 60 revolutions per second = 50 revolutions / second = 100 sparks per second

THEREFORE a digital tachometer can expect an input of 100 Hz at 3000 rpm ??

Have I got this right guys?

The reason I ask is I want to set up the digital tacho I have built. I can feed it known frequencies from my computer for calibration, but I want to get the frequencies right :D:D:D


Title: Re: Frequency Calcs - Sanity check please
Post by: ROD on May 20, 2013, 08:11:26 PM
Sorry,you lost me there. My digi tacho only needed setting for 4 cyls,and it worked.


Title: Re: Frequency Calcs - Sanity check please
Post by: Olds on May 20, 2013, 08:45:46 PM
Logic seems fine to me.


Title: Re: Frequency Calcs - Sanity check please
Post by: andyrennison on May 20, 2013, 08:54:21 PM
Cheers ON, it is 2 firings per revolution then - that's the bit I wasn't sure about :) . Rod, I built the electronics for the tacho using a frequency to voltage convertor, and a bar graph driver chip, so it really is "home built" :)


Title: Re: Frequency Calcs - Sanity check please
Post by: Manky Monkey on May 20, 2013, 08:55:20 PM
...huh?


Title: Re: Frequency Calcs - Sanity check please
Post by: andyrennison on May 20, 2013, 09:18:55 PM
 :) :) :)


Title: Re: Frequency Calcs - Sanity check please
Post by: Manky Monkey on May 20, 2013, 09:24:19 PM
Does it have flashing lights?
I like flashing lights.  :P


Title: Re: Frequency Calcs - Sanity check please
Post by: andyrennison on May 20, 2013, 09:29:37 PM
Oh yes, in a circle round the outside of the clock :)


Title: Re: Frequency Calcs - Sanity check please
Post by: morrag on May 20, 2013, 10:15:16 PM
Well, that's alright then........................... ??? ??? ??? ??? ??? ??? ???