Most likely the motor is drawing lots of current at start-up thus it drains the cap on the 12V line and the system, so the regulator cant maintain a good 5V if the 12V is unstable...
simplest fix... get a BIG capacitor, a few hundred uF (470uf+ or 1000uf if its a bigger motor) on the 12v side...
Hey!
Humm i have built numerous things, some don't have a category but were project specific. Mostly its been function/signal generators, arbitrary generators,linear power-supplys, numerous forms of data loggers,data bus decoders and some temperature/environmental monitors.
Hey guys, I was recently thinking about the tools I design for personal use and thought that perhaps I should expand and offer them to others at a low cost.
I wanted to get a better idea of what some of you guys value in test equipment and tools before I commit any serious work into making them...