That's called using a capacitor and a resistor to protect the diode design. ;D
People who can't fit a driver or simply don't want to make one use a resistor to limit the current going to the diode and a capacitor to protect it from spikes. The only problem with this is that it's not regulated, so as the batteries get weaker so will the LD.
People who can't fit a driver or simply don't want to make one use a resistor to limit the current going to the diode and a capacitor to protect it from spikes. The only problem with this is that it's not regulated, so as the batteries get weaker so will the LD.