[Diy_efi] WB Integrator testing

William Shurvinton shurvinton at orange.net
Sun Apr 28 23:16:15 GMT 2002


Hi,

Just finished an evening of diagnosis. The integrator on my DIY-WB wasn't.
Now this may be due to the fact that I scrounged my parts from the lab,
rather than ordering the exact ones specified on the web site, so bear this
in mind.

Anyway when you connect Vs to Vref the voltage doesn't drift down as
expected. This is due to the LM324s I am using not behaving as perfect unity
gain buffers. I haven't analysed exactly why yet as I don't have the spec
sheets on the ones I got, but you get about 20mV difference between input
and output when configured as a unity gain buffer. This is enough such that
when you close the switch to do test 34 pin 10 of U2 is positive wrt pin 9
and so the integrator will stubbonly stay at 2.7V.

I need to sleep on it to think if this will actually effect operation, but
thought I would pass on the findings so far in case anyone else had found
this and was confused.

Apologies if this was covered 6 months ago and I  missed it

Bill


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi


More information about the Diy_efi mailing list