DIYEFI.org Forum

Yes! :-)

1) Verify latency with 10k/10k/1nF input setup and 5V square wave signal on VR+ with VR- floating
2) Verify reduced latency with capacitor removed and same setup
3) Fix VR- @ 2.5V and measure latency
4) Still fixed @ 2.5V, reinstall cap and measure latency
5) Still fixed @ 2.5V with cap, reduce resistance from 10k to 1k and measure latency

I can't think of more things to try with it than that, but if you can, feel free to play around more! :-)

Fred.

No probs! Will do ASAP!

Just ordered a Saleae Logic16! (3-5 days delivery)

Will keep you posted!

Those are cool, and quite big! :-) I look forward to seeing pretty photos of your bench + it.

sweet! glad I made a "good" choice then. The Open one you told me about just looked a little tacky. . . . LOL

Yes, we've all seen your valve cover ;-)

What we haven't all seen is the car that your Mrs has! :-o

Another thing to try is watch the floating negative pin with the second channel of a scope and see what it's doing. I have a hunch that even without the cap it is moving around a lot. Hence the suggestion of fixing it at 2.5V and watching the latency then.

my Logic16 just arrived

testing to follow soon!

While you're at it, how about testing 1k instead of 10k for the input resistors, with std cap and floating -ve, i bet it's still bad. Prove me wrong :-)

My Test Results in the form of traces from my Logic16 are as follows, in order of tests requested.

1) Verify latency with 10k/10k/1nF input setup and 5V square wave signal on VR+ with VR- floating



2) Verify reduced latency with capacitor removed and same setup



3) Fix VR- @ 2.5V and measure latency



4) Still fixed @ 2.5V, reinstall cap and measure latency



5) Still fixed @ 2.5V with cap, reduce resistance from 10k to 1k and measure latency



and a new item,

6) With cap and two 10k resistors, feed square wave into VR+ and same inverted square wave into VR-

Just to be picky, I will also throw up some LA traces with actual latency measurements.

2) Verify reduced latency with capacitor removed and same setup - with actual lag time



3) Fix VR- @ 2.5V and measure latency - with actual lag time



4) Still fixed @ 2.5V, reinstall cap and measure latency - with actual lag time



5) Still fixed @ 2.5V with cap, reduce resistance from 10k to 1k and measure latency - with actual lag time



6) With cap and two 10k resistors, feed square wave into VR+ and same inverted square wave into VR- - with actual lag time