Hi everyone. Been a while since I've been here. Work has been keeping me from electronics for a year or so. As I was only just beginning to learn a thing or two, before I was pulled away, I fear I'll have to start all over.
Anyway, I'm working on a small project for which I needed a blower fan. I salvaged a squirrel cage blower from a copy machine a couple years ago and thought it'd be ideal for my little project. It draws a little over 3/4 amp, according to the tag. There are 3 conductors, black, red and yellow. I expected black and red to be negative and positive, with white as a speed sensor. Unfortunately, the motor rotates a few degrees and stops. Spinning the squirrel cage with voltage applied doesn't help. Bearings seem okay and cannot detect any physical blockage preventing rotation. Rotates easily by hand, but "steps" every 90 degrees.
I can see the edge of a small circuit board inside, but the case is riveted. Before I drill out the rivets and inspect it, I thought I'd ask if there's the possibility I'm doing something wrong. I'm assuming the pcb is just part of the speed sensor. Is it possible the pcb does more? Like, senses voltage to protect the motor? I'm using an old laptop ps, 19vdc 3000mA. Wasn't planning on it as a permanent solution, just testing the fan. Or, is the yellow wire something other than speed sensor? Could it be a stepper with the case as a conductor? I can feel 4 "steps" per revolution if I rotate by hand.
Thanks for the input