Jaguar Prototype Testing

[Fred]

Andy, stop guessing and attach the saleae to that thing on both sides of both optos! :-p Instant definitive results! ;-)

[Dan]

eagerly awaits testing results!

maybe we are not driving the opto leds hard enough by limiting the current through them too much? our resistor values may be too high me thinks.......

[DeuceEFI]

Here are the Saleae results, channel 1 is the TX line from the MCU, channel 2 is the output from the opto. The filename that starts with Ravage is the Ravage opto circuit and the filename that starts with CEL is from the manufacturer datasheet. Both give me framing errors...

[TonyS]

Do you have a scope that you could hook up in place of the Saleae logic analyzer? Thanks

[Fred]

I guess you're thinking that the edges are rounded over? I was going to give you shit for not opening the files. Perhaps you did, though? Viewer here:

http://www.saleae.com/downloads/

[Fred]

Andy, great logs!

The rav one is useless and the other one shows a consistent 8 to 10 microseconds of lag on the going high side, but it turns off almost instantly.

What are the CEL resistor values? At first glance it looks like it simply won't work and we need to find another part. Unless your circuit is somehow dodgy?

Great testing, on behalf of everyone: THANK YOU VERY MUCH! :-)

PS, plus one on a scope trace, now that I've had a look at the LA traces.

Fred.

[DeuceEFI]

Optocoupler Update:

I used the CEL recommended 50ohm resistor to ground on the input and 100ohm resistor on the emitter output, I tried various resistances on the emitter output between 100ohm and 5kohm per CEL's datasheet and the larger the resistance I used past about 220ohms, the waveform on the output degraded to nothing but framing errors on the LA and a badly formed sawtooth waveform on xoscope.

I checked the input and output with both the LA and with xoscope and Huff was correct in wanting to see the raw waveform, it wasn't a nice squarewave going in or coming out the opto, instead the input had a LC ramp up from 0v to 5v which caused the delay in the beginning of the output waveform and why it dropped off quickly after the input went back to 0v.

I will surf the web later on this evening to see if I can find other people (after a quick 30 second Google search it appears the Arduino people have tried this, I just need to find a complete writeup of their testing...) as I would like to have this on my Jaguar board and I know Dan would like to have it for his Ravage board, so I will keep looking for a solution.

Unfortunately my 30-something year old digital o-scope died a few days ago during initial testing of the circuit, so I'm in the market for a replacement o-scope... I got 25 years of use out of it, so I think I got my money's worth

[Fred]

That's really shit! Those were supposed to be fast parts. You are using the correct parts, right? Part number?

[Dan]

should be NEC manufacturer part no. PS2911-1-F3-A

E14 Link - http://au.element14.com/nec/ps2911-1-f3 ... dp/1682872

DeuceEFI - can you confirm you have this exact part?

[DeuceEFI]

Manufacturer: CEL
Manufacturer Part number: PS2911-1-F3-A
Digikey part#: PS2911-1ACT-ND
URL: http://search.digikey.com/us/en/product ... -ND/770728

The datasheet looks identical with the only difference being the Manufacturer and their logo...

The manufacturer marking on the component is "N"

view from top of component:

11_
N
047

and according to the E14 NEC datasheet it is the IDENTICAL part, right down to the manufacturer mark.