The recommended phototransistor APT2012P3BT is not so sensitive for visible light, it is much more sensitive for infra red light. Is it actually a suitable light sensor for blink up?
Phototransistors are indeed most sensitive to IR, this appears just to be a characteristic of the silicon.
This is why you should get one with a clear lens - there’s still plenty of visible light sensitivity there.
The APT2012P3BT self is black. So the APT2012P3BT should have enough sensitivity for visible light?
Hmm. That’s the wrong PN. The right PN would appear to be AP2012P3C (C=clear lens). Will get the datasheet fixed.
AP2012P3C is not available at Digikey or Mouser. So I think I will pick the other recommended photoptransistor Everlight PT17-21C/L41/TR8
Have used the PT17-21C/L41/TR8 with 100k emitter resistor (i.e. the Nora design) several times without issue.
That one is sensitive for both visible as IR so should be good. If you want a smaller version of the same then you can pick the PT19-21C/L41/TR8
Nice … thanks for the lead … will switch up to this device.
I designed and ordered a little blinkup breakout board with 3 different footprints for phototransistors.
Wow, thanks for pointing this out jrsikken
Did not see this in time and can confirm the APT2012P3BT is a pain to get working. Wondered about the dark lens, and looking at the component data sheet, it is no wonder as visible light is blocked quite well.
In the latest IMP datasheet KDT00030TR replaces APT2012P3BT
Thanks for PT19-21C/L41/TR8 with 100K resistor - working well.