Attach your test load to your driver output (the end with resistor goes to + and the other end goes to -)
Then you should put your multimeter to voltage. Try using the lowest possible value available.
Well.. to put it out short: highly dangerous, invisible and thus mostly useless stuff - ofcourse ;)
Whadd'ya thought?
Edit.
I found some current calculator tool and made an regulator with it (see attachment). Now my question: will this schematic work or shall I use another one? Also, which one...
So, I bought 3 of these:
Wavelength : 808±10nm
Power Output : CW 300mW
Working Current(mA) : ≤400mA
Working Voltage(V) : 2.2V
Working Temperature ( ℃ ):-10~+40
Threshold Current (mA):≤120
Beam Divergence (deg): Θ// :17 . Θ⊥38 .
Sealed Size : TO18(5.6mm)
Life span : >10000 hours
Now Im...