A while ago, my roomate broke his laptop. It wouldn’t charge, but it wasn’t something obvious like a busted charger or anything like that. So, I helped him move all of his important files to a new machine, but I haven’t had time to look at the old one for a while. Now that I’m starting to settle in at my new job, I have a bit more free time at the end of the day when I get to play with projects.
A few weeks ago, I fixed the issue with the protection circuit. I forgot to document the repair, so I’m going to go back later and write up what the issues were if anyone else needs to read that. Since then, it’s sounded pretty good, but recently after a while of listening (about 1-2 hours) the left channel will drop out due to some noise. It makes it unbearable to listen to, and the volume knob doesn’t do anything to lower the static, just the right channel.
Continue reading “Pioneer SA-9100 noisy channel”I got this clock from a flea market, Rodgers, in Rodger, OH. I think I paid $7 for it in a broken condition.
When plugged in, it still hummed, giving me hope that it was still repairable. After opening, it looks like this magnetic flywheel has become deformed, or some other problem, and it doesn’t spin freely. Some googling shows these are actually pretty neat motors- they are single phase, synchronous motors. So, the AC waveform from the wall into an electromagnet creates the dipole necessary for driving the flywheel forward, no transformer or phase regulator needed. This is nice and convenient, since mains is 60Hz, the rest of the motor is just a 60:1 and then another 60:1 gear reduction, so that the motor is making 1 rotation per minute, advancing the dials.
If we can replace the flywheel, and the motor has enough power to give it the correct RPM for the main spindle to reach 1 RPM, it’ll be good as new!
Continue reading “numechron clock restoration, flywheel replacement”