audioguru Posted February 27, 2006 Report Share Posted February 27, 2006 Hi,This was realy quick and professional... Very nice Quote Link to comment Share on other sites More sharing options...
Untitled_user Posted February 28, 2006 Author Report Share Posted February 28, 2006 Hi,well, i really don't know wich ones to take... never had experience with photo elements before... but, its time to change it...I atached a list of elements from our 'local' shop... don't worry, it's only about 30 of them... ;D And I'm soory if the choice is bad... we don't have much electronic stores, and what we have is ussualy expensive... Hope it's gonna change some day...So, please find something for me...Have a nice day... opto.txt Quote Link to comment Share on other sites More sharing options...
Untitled_user Posted March 4, 2006 Author Report Share Posted March 4, 2006 Audioguru? Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 4, 2006 Report Share Posted March 4, 2006 Hi Marc,Many of the opto items on your list are "Optical Isolators" which have its LED shining internally on a photo-diode or photo-transistor and therefore can't be used as a tachometer.Go through your list and sort them at www.datasheetarchive.com . Quote Link to comment Share on other sites More sharing options...
Untitled_user Posted March 4, 2006 Author Report Share Posted March 4, 2006 Hello,sorry about theese opto isolators...Here is the filtered list...opto.txt Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 4, 2006 Report Share Posted March 4, 2006 The BP103 photo-transistors have a very wide 55 degrees pickup pattern. Any of the other photo-transitors on your list have a much narrower pattern and would be fine.I am sorry but I didn't look at all the photo-diodes. Some might be an optical emitter , others only infrared which you can't see and others might be a detector instead of an emitter. Quote Link to comment Share on other sites More sharing options...
Untitled_user Posted March 4, 2006 Author Report Share Posted March 4, 2006 OK, and thanks a lot! I will buy parts as soon as i get and assembly this circuit...Till then...Cheers! Quote Link to comment Share on other sites More sharing options...
Untitled_user Posted March 10, 2006 Author Report Share Posted March 10, 2006 Hi!I'm back again. I assembled the counter... ;)Tooked BPW40 and ordinary white LED.And of course, there are the problems...1. It works just fine when I put the diode on one side of rotating disc and transistor on the other, and cut a hole in disc so Tr can 'see' diode in one moment of rotation. (excuse me for bad description, hard to me say it in English :'()... But when I try to put them both on the same side and use reflection from white/black area, it doesn't react. What can I do?2. OK, this one I belive can be done later, but anyway: how to calibrate the meter?Regards Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 11, 2006 Report Share Posted March 11, 2006 Your white LED is really a blue one with a yellowish phosphor, and doesn't match your phototransistor's color response very well. It can be made much more sensitive:1) The phototransistor can be made more sensitive by increasing the value of R4. The resistor at pin 2 should also be increased so that its value is up to 10 times higher.2) The LED can be made brighter by decreasing the value of R3 to 220 ohms for the white LED that probably has a forward voltage of 3.3V to 3.6V and a 9V supply. Quote Link to comment Share on other sites More sharing options...
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