Hi
I'm looking for advice on choice of a sensor. Requirements are physical, really. I've looked in the catalogs but maybe someone more up to date than me has an idea.
I want to sense a small LED blink. It's on the back of a camera, only about 3mm high, and I want to trigger something off its on and off edges. It stays on something like 20ms. Not bright, something slightly brighter than the HD led on my desktop. In the old days I would have said it's about the brightness of a 3mm led with about 2 mA going through it, but I'm way out of date. I drew the red dot on the image, the "lens" is translucent colourless.
So I'm looking for something with a risetime quick enough to not be an issue, maybe 100us. As you can see there's nothing much to attach it to. I was thinking of magnetic tape. I don't want to use the tripod screw, that'll be used, and I need to be able to remove it easily.
I can botch a two-legged thing on to a thin flexy wire and hold it there with PVC tape, but that's a bit yuck.
I'll need to trigger a 555, or something like that, and it would be nice to be able to "gate" it, or use a wired-AND, as there are no spare logic chips being used.
So - photo resistor/diode/transistor? Fiberoptic?
Any neat ideas?
Now, will this image upload...
I attached it - is that good?
I'm looking for advice on choice of a sensor. Requirements are physical, really. I've looked in the catalogs but maybe someone more up to date than me has an idea.
I want to sense a small LED blink. It's on the back of a camera, only about 3mm high, and I want to trigger something off its on and off edges. It stays on something like 20ms. Not bright, something slightly brighter than the HD led on my desktop. In the old days I would have said it's about the brightness of a 3mm led with about 2 mA going through it, but I'm way out of date. I drew the red dot on the image, the "lens" is translucent colourless.
So I'm looking for something with a risetime quick enough to not be an issue, maybe 100us. As you can see there's nothing much to attach it to. I was thinking of magnetic tape. I don't want to use the tripod screw, that'll be used, and I need to be able to remove it easily.
I can botch a two-legged thing on to a thin flexy wire and hold it there with PVC tape, but that's a bit yuck.
I'll need to trigger a 555, or something like that, and it would be nice to be able to "gate" it, or use a wired-AND, as there are no spare logic chips being used.
So - photo resistor/diode/transistor? Fiberoptic?
Any neat ideas?
Now, will this image upload...
I attached it - is that good?
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