Red laser driver with a single cell

[Driverterminator]

is this the same scheme right? Because i get confused with more resistors... i found an opamp rail to rail "1,8 to 6 volt range" NJM2732D. is it better?

There is also an opamp NJU70 series. For exemple the NJU7095D wich can work from 1 volt to 5,5 volt. but it's not rail to rail. Does it matter?

 

[rjenkinsgb]

It's a similar concept, but missing the parts to set the current (via the control voltage).

The opamp must be a type that can provide enough output current to drive the transistor. The one I picked has an output current of up to 80 mA which is quite rare.

The opamps you mention have much lower output current ratings & could not directly drive a power transistor, sorry..