I want to use this phototransistor in an Arduino project: https://www.kingbrightusa.com/images/catalog/spec/WP3DP3BT.pdf I calculated the value of the phototransistor bias Resistor (R1) by the following computation:
R1 = (Vs - Ev) / If
where: Vs = supply voltage, which is 5V on Arduino board Ev = emitter forward voltage, which the data sheet states as 0.8V If = emitter continuous forward current in Amperes, which the data sheet states as 100nA Applying the formula, we get the following:
R1 = (5V - 0.8V) / 0.0001A R1 = 42K ohm then I used R1 =10K ohm to use the phototransistor as switch (either saturate or cut state). I am not shure from my choose.
So, my question is:
- Did I compute R1 and choose it correctly?