18436572

I am building an ecm bench and I am having a problem simulating the pickup coil in the dist. I built a simple 555 timer circuit. The circuit does work and it showes rpm on my scan tool but I can only simulate rpm up to 1050. Does anyone have a diagram that I could take a look at to help me find out what I am doing wrong?
I have searched the archives and have not come up with any useful info. A link to a thread that discusses this would be great.


THANKS,

SATURN5

A 555 will do the job, you just need to adjust your RC values to get shorter pulse widths. Google up for calcs that will give you the values for a given frequency range. BW

18436572

Thanks for your reply SATURN5. I guess that your going to have to babysit me here(what does "RC" stand for?). Please excuse my ignorance.

THANKS,

SATURN5

Resistors and Capacitors. The ratio of these values determines the output frequency range of the 555. There are programs available on the net (free) that will help you figure out what values are best for the frequency range you need. BW

HighHopes85

Ran across this one a while ago while I was hacking up a stopwatch, trying to control it's start and stop functions.

http://ourworld.compuserve.com/homep...Bowden/555.htm

HTH

Edit-I figured I would throw these out...tons of 555 stuff on the net. This is just some of the simple stuff.

http://www.play-hookey.com/digital/timer_555.html

http://www.iguanalabs.com/555kit.htm

http://www.williamson-labs.com/555-circuits.htm

And this last one is a program that you could simulate the 555 with.

http://www.schematica.com/555_Timer_design/555.htm

18436572

Thanks SATURN5 and HighHopes85. Did a google,downloaded some software and a few hours of R&D now my test bench spins at 6375 RPM. I found some realy cool software had a lot of fun and I learned a bunch (thats the best part),.

Thanks again,