Throughout this senior project experience, we've had some pretty hilarious times. One of the MOSFETs that is currently on the project released some smoke the other day.... but is still working just fine. I was just impressed. Our motor controller is quite possibly the most terrifying and terrible motor controller ever slammed together to meet hilarious specifications. This is how senior project has worked for years and will continue to work.... students pull specs out of their butts about something they know little to nothing about, professors say "yeah.... sure... that sounds doable" and then it's not. Due to this fact, our motor controller is hilariously bad but does meet the outlined specs and the kids next to us are making gigantic square waves instead of a functional inverter. Some other group spec'd a project that sounded challenging and then proceeded to use an off the shelf servo motor, send it a PWM and watch it move to a different angle. The project range from an awesome coil gun that is controlled via an android app to a lead acid battery charger that was essentially a circuit found online.
Project difficulty variations aside, I have been learning a bunch by doing this project which has been sweet even though it has kind of consumed my everything. Here is a picture from yesterday of our solder board for C grade... we added a couple BAMF diodes (technical term) today.
Check out our awesome photo-tachometer that I picked up at Harbor Freight in NH. Why was I in NH you may ask? Great question.... more on that soon. More rant about senior project.
Our motor controller is hilariously bad and good at the same time. It draws essentially full current at all RPM.... yes.... that means full power all of the time. For those of you not well versed in the land of brushless motors, it makes things a lot simpler. We essentially vary the frequency (and kind of the magnitude) of the 3-phase voltages applied to the motor using PWM and sine wave lookup table to control rotor speed. There is no REAL control algorithm, it is running open loop but the great thing about brushless motors is that when they are under load, the back EMF decreases which means it draws more current.... which means it produces more torque.... which means it essentially tries to maintain the same speed it is being driven at by its self (within reason). Basically, brushless motors are complicated and badass. If I could do this project again I'd do it much differently but it has been cool. We will probably be making a PCB for it which will be sweet.
Anyways, so last thursday night I drove down to Wilmington, MA for an interview with Analog Devices. I stayed in this hotel that was right across the street from Raytheon. We were (still are) right in the thick of senior project so it was hard for me to pull myself away to go just because we had so much to do but I went. I was thinking it wouldn't be that cool but I was basically very wrong. They gave us a kind of drink the Kool-aid speech at the beginning which was kind of interesting but the folks I interviewed with just seemed very nice. I got a tour of the lab and test facility and I was pretty blown away by the stuff that they do honestly. The group I interviewed with makes analog to digital converters for various things, many are for high precision applications. Some of the layers on the chips are separated by 5 atoms..... Yes. 5. Atoms........ Atoms. If they miss one atom it is a 20% error. I was pretty blown away honestly and very impressed with the work being done there. The interviews (all 5 of them) went pretty well though so maybe I will hear from them in the next couple of weeks. I don't know much about ADCs, but I could be willing to learn... it was pretty amazing stuff.
Also on the "What the heck is Tony doing after graduation front", I was given a sort of informal job offer from the guys at Pika Energy this week. Pretty relevant timing, with the whole Analog interview and all. Still haven't taken the GRE..... or registered for it.... Not sure about grad school. Just not sure. I may have to make some pretty big decisions on all of this stuff in the next couple weeks. I guess this is what adults do?.....
Oh, I also got a new (to me) car! 2005 Subaru Forester with 105k miles on it in pretty good shape. The check engine light came on the other day though and the cruise control stopped working...... I also have a tail light out suddenly. Hey, still better than my old car! This one has heat AND a radio!
Wow I wrote a lot.... Google hangout soon to help me figure out what to do with my life!
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