Question about power supply

hey, im gonna build a diy laser and i wasnt sure wether to use batteries or a mains adapter that changes the power to 3v DC ?

thanks

That has to be your choice, which ever way you go you will need to build a drive circuit ( 3vDC supplys are not constant current). You may just get away with a limiting resistor but I would not advise it.....

Regards rog8811

ill use batteries and a 10ohm resistor in that case, to save all the hastle lol