New answers tagged phototransistor
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DIY pulse oximeter circuit - phototransistor shows no reading
Required:
Narrow beam LED https://www.digikey.ca/en/products/detail/ams-osram-usa-inc/SFH-4550/806365 6 deg or similar
Narrow beam Daylight blocking IR PD 20 deg. & a narrow beam RED LED
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DIY pulse oximeter circuit - phototransistor shows no reading
The SFH 203 IR diode you list is a photodiode, not an LED. It's meant to be used as a sensor, similar to the SFH-313-FA phototransistor you are using. I'm not sure what should happen if you try to use ...
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DIY pulse oximeter circuit - phototransistor shows no reading
Since the camera of a cell phone is sensitive enough to verify that the IR LED is working, I strongly suggest doing that. Just open the camera app on your phone and hold the IR LED into the camera. If ...
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Photointerrupter with internal pull up Circuit design
Resistance of the internal pull-up on these PIC micros isn't well defined, since it isn't technically a resistor, rather it's implemented by some kind of transistor arrangement exhibiting what looks ...
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Photointerrupter with internal pull up Circuit design
I suggest you turn off the pullup and depend entirely on an external 1% resistor.
With all the variations associated with optocouplers (LED aging, dirt in the gap, temperature changes), who needs an ...
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