MicroVoltage fuse (Now "Sensing the Flame-Front of a Plasma")

[Averagesupernova]

No disrespect intended but the fact that the OP was expecting to blow fuses through a flame leads me to believe ANY of this is above their head. Basic electronic troubleshooting skills seem to be absent. It is very difficult to help someone with something like this with the level of experience that is apparently lacking. To expect folks on an internet forum to be able to fix this under those circumstances is expecting a lot and to do it with no pictures is about impossible. Folks with the same general understanding of electricity that are on opposite sides of a keyboard/computer screen can accomplish something but this seems rather pointless. Again, no disrespect intended. I wish I knew more about what the OP is doing because it interests me. I have had little experience with flame sensing besides thermocouples and cad cells, and the fact that I know microvolt/microamp flame probes work since they are in many furnaces.

 

[sophiecentaur]

I have had little experience with flame sensing

Me neither but I would have thought that an IR imager would be the way to do it. A video camera with a filter over the lens which just passes IR would give a time resolution of better than 20ms and nothing special would be required in the way of experimental equipment,
Of course, there is nothing wrong with negative experimental results so the difficulties constitute a learning experience.

 

[Asymptotic]

No disrespect intended but the fact that the OP was expecting to blow fuses through a flame leads me to believe ANY of this is above their head. Basic electronic troubleshooting skills seem to be absent.

A fair point, although I've known freshly-minted techs straight out of school who had yet to experience their first "real world" design and diagnosis cycle, and found themselves in similar straits.

Troubleshooting heuristics aren't necessarily taught in school, and I've seen otherwise capable folk overwhelmed by their first foray into the field. One of my favorite books on the subject is "Debugging" by Dave Agans (although there's a soft spot in my heart for Polya's "How to Solve It"). This poster from Agan's website sums up the rules quite nicely.

 

[Averagesupernova]

A fair point, although I've known freshly-minted techs straight out of school who had yet to experience their first "real world" design and diagnosis cycle, and found themselves in similar straits.

Troubleshooting heuristics aren't necessarily taught in school, and I've seen otherwise capable folk overwhelmed by their first foray into the field.

You are quite correct. I was once in that position. That does not change the basic scenario. When I was in that situation being a greenhorn I could not have imagined trying to solve it in this manner. I needed some side by side guidance.

 

[jim hardy]

I'm really suspicious of software . It was not my field and i know just enough to be dangerous.

Absolute value of signals wired single ended and read differential ?
Indexing mistake reading that FIFO buffer into an array to plot ?

When you can't see what's wrong you have to make everything prove itself right.
Test the data acquisition with something that's too simple to fool you. Like the microswitch from a microwave oven door - there's plenty of them in trashpiles. When you can see the contact bounce for about a millisecond you have achieved good data capture.

Then characterize the flame detector signal by measuring one gap by itself at high speed with no averaging or smoothing..
I searched for high speed photography of a flamefront but the sites all wanted seventy-nine dollars to view it.

old jim

 

[jim hardy]

You are quite correct. I was once in that position. That does not change the basic scenario. When I was in that situation being a greenhorn I could not have imagined trying to solve it in this manner. I needed some side by side guidance.

Yes, we all started as greenhorns. It's too easy to forget how mysterious it seemed at first.

 

[Tom.G]

A video camera with a filter over the lens which just passes IR would give a time resolution of better than 20ms and nothing special would be required in the way of experimental equipment,

His experimental run lasts 15ms.

 

[Rive]

His experimental run lasts 15ms.

Yeah. The equipment actually fits with the task, it's just not known what it does and how should it be used...