I'm working with a couple different diode lasers, attempting to automate control of them (on and off mainly) by modulating the source currents externally. One of them is a green laser that draws ~1.4A, 3.3V but has no modulating chip in the power line. I've got another smaller red laser module (draws ~50mA @ 3.3V) which does have a transistor in the line with a 0-5V analog input to modulate the current. I figured that since the company I got this module from assures me that the transistor can handle a couple amps through it, I should be able to cut the wires on either side and splice the transistor into the green laser power supply. However I'm in the middle of the splice job and have a (maybe stupid, maybe major) concern: The wires used for the low-power laser (coming out of the modulation control transistor) are very small and I'm not sure that they'll be able to handle the higher current for the green laser (1.4A). Will I have problems with the modulation working reliably as a result of this?? If this modulation scheme sounds silly, could anyone suggest a good transistor or switch to use for regulating current with a 0-5V input?