Modular Optical Sensors
May 14, 2013 7:28 AM Subscribe
In my previous question about photo/optical detectors I received a LOT of great advice and I'm back for more.
Here is a link to the previous question if you are interested:
http://ask.metafilter.com/212785/Please-help-me-see-the-light
I found out a lot of things that work and things that don't work since then. What I'm struggling with is finding decent optical sensors in packaging that I can mount. I found this company (AutomationDirect) that sells a fairly wide range of modular optical sensors but they all seem to be geared towards "laser trip wire" type setups. I love the packaging and that is what I'm primarily after but I'm interested in getting an output that is proportional to the light level the sensor is seeing.
What I've been using so far are the LTR-301 phototransistors. These are meant to be PCB mounted, but instead I've soldered the through-hole leads to wires and fixed the sensor in place using Teflon (PTFE) mounts between screwes. This is just too problematic from a stability standpoint. I need basically what I've got in better packaging and I don't have the skills (or time) to develop that myself. I'm seeing now that the cost of these optical sensors is mostly in the packaging as the electronics in these are pennies.
For this particular application, I'd like to be sampling the sensor at a rate of 2kS/s - 10kS/s.
Thanks for your advice and any further correspondence that you can provide.
Additionally, I DO have some "laser-trip-wire" projects and am looking for additional resources for those kinds of components (like the ones I linked to from Automation Direct).
Here is a link to the previous question if you are interested:
http://ask.metafilter.com/212785/Please-help-me-see-the-light
I found out a lot of things that work and things that don't work since then. What I'm struggling with is finding decent optical sensors in packaging that I can mount. I found this company (AutomationDirect) that sells a fairly wide range of modular optical sensors but they all seem to be geared towards "laser trip wire" type setups. I love the packaging and that is what I'm primarily after but I'm interested in getting an output that is proportional to the light level the sensor is seeing.
What I've been using so far are the LTR-301 phototransistors. These are meant to be PCB mounted, but instead I've soldered the through-hole leads to wires and fixed the sensor in place using Teflon (PTFE) mounts between screwes. This is just too problematic from a stability standpoint. I need basically what I've got in better packaging and I don't have the skills (or time) to develop that myself. I'm seeing now that the cost of these optical sensors is mostly in the packaging as the electronics in these are pennies.
For this particular application, I'd like to be sampling the sensor at a rate of 2kS/s - 10kS/s.
Thanks for your advice and any further correspondence that you can provide.
Additionally, I DO have some "laser-trip-wire" projects and am looking for additional resources for those kinds of components (like the ones I linked to from Automation Direct).
Response by poster: Hi FauxScot - Yes, I noticed that AD's stuff is heavily filtered and actually is TOO filtered for my trip-wire requirements. I need something in the >100kHz range for that application.
For my light sampling application where I'm observing the light levels of a chamber what I am responding to is the presence of fire within the chamber and I expect an ignition event to last on the order of milliseconds in order to be considered "significant". For that application, speed isn't as important.
posted by nickerbocker at 9:23 AM on May 14, 2013
For my light sampling application where I'm observing the light levels of a chamber what I am responding to is the presence of fire within the chamber and I expect an ignition event to last on the order of milliseconds in order to be considered "significant". For that application, speed isn't as important.
posted by nickerbocker at 9:23 AM on May 14, 2013
Response by poster: Hi b1tr0t - Yes, I have but my boss wants me to explorer what is out there and auto fabricated and ready to go. So that is where I'm currently at. Thanks for your input.
posted by nickerbocker at 9:26 AM on May 14, 2013
posted by nickerbocker at 9:26 AM on May 14, 2013
This thread is closed to new comments.
Automation Direct is a good outfit, but they are into industrial controls. A lot of them don't want super high speed responses and intentionally filter and decrease response times to avoid transients.
However if you think you have the PERFORMANCE you need from your prototype and your like the PACKAGING you see at AD, you might want to consider buying a unit from them and scrapping the internal electronics. It's a valid approach for one-time designs and I do it all the time for many different components.
memail if you have specific questions and i would be happy to help.
posted by FauxScot at 8:14 AM on May 14, 2013 [1 favorite]