$20 PTX Flame Sensors for TCFFRC
I just found a source for an obsolete Fairchild phototransistor that is·particularly sensitive to detecting candle flames. I used these successfully·at the very first Trinity College Fire Fighting Robot Contest in 1994: first place with a BS-1 powered·robot! The Fairchild part number is FPT540A. I have to buy·20 of them·to get the price down to $20 each. I only·want 3, so I'm curious if anyone else wants to buy any to split costs. I'll only order them if I can find a few interested parties.
FYI,·my 1994 robot·used·two phototransistors; one looked left of center, the other right.··Each·was·in a seperate voltage divider arrangement to·feed varying output voltages into an LM339 comparator, and·each had a·pot adjusted to give a useable reference voltage. This arrangement gave digital high/low signals to sense the flame, and was obviously sensitive to the pot adjustment. I'm now of the opinion that it would be better to use the phototransistors in an RCTIME arrangement (similar to a pot or photocell) to yield analog measurements which could be compared to background light levels.
If anyone is interested in buying some of these, please PM me. No profit here, I'm selling these at my cost, $20 each.
Alternatively, if anyone can find these parts for less than $20, let me know and I'll buy them from you!
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·"If you build it, they will come."
FYI,·my 1994 robot·used·two phototransistors; one looked left of center, the other right.··Each·was·in a seperate voltage divider arrangement to·feed varying output voltages into an LM339 comparator, and·each had a·pot adjusted to give a useable reference voltage. This arrangement gave digital high/low signals to sense the flame, and was obviously sensitive to the pot adjustment. I'm now of the opinion that it would be better to use the phototransistors in an RCTIME arrangement (similar to a pot or photocell) to yield analog measurements which could be compared to background light levels.
If anyone is interested in buying some of these, please PM me. No profit here, I'm selling these at my cost, $20 each.
Alternatively, if anyone can find these parts for less than $20, let me know and I'll buy them from you!
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·"If you build it, they will come."