[Diy_efi] pulse readings: correction.

[Phil Hunter]

> ... Do you want to read my sometimes not fully thought out ideas...?

Nothing personal, but my preference is quality over quantity. Plenty of folks
on these lists can give you vague, misleading, one sentence answers, it's the
"quality" posts, even if they are brief, that catch my attention.

If you use the archives at all, I'll think to see where I'm coming from. The
over-all quality just isn't here like it used to be.

> ...Threads don't stay around long usually,...

Not much I have to say is so important it can't wait a day or two. And threads
last longer in digest mode and a lot longer in the archives.

Another option to consider is sending a reply directly to the sender,
sometimes that's more appropriate.

> ...  2 LED's with dropping resistors, one forward biased, one reverse,
> in parallel, avoids a mistake in polarity.

You can get Bi-colour LEDs made this way (2 leads, vs. the 3 lead type),
they tend to be weak in intensity, but now there are Red-Green-Blue super
bright LEDs available. I'd suggest the diffused ("milky") type for most of
our applications.

Or use a bridge rectifier, my first thought for the opto-isolator in the
Pulse Width project rather than the special one Steve chose.

Your suggestion of using an LED is much safer than a speaker for testing
logic circuits, few are designed to drive such low impedances as speakers.
Logic Probes are probably an even better thunk.

> ...the LED will seem almost steady, but look carefully, you can see the
> flicker.  

One trick to try is to scan your eyes across the LED, sorta like looking
straight ahead and then turning your head quickly. The persistance of your
vision can let you see the flashes and might even give you a relative
indication of duty cycle. Or it may only make you dizzy <grin>.

rgds,
phil
(digest)

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