Simple Universal Motor Speed Controller

I finally had time to get the Rev-II board etched last night.  Still need to electrical test the traces, drill the holes, apply the top mask, and populate it.  Unfortunately, I have a funeral and such this weekend, so maybe I'll have time next week to work on it some more.  Stay tuned!

Eagle files have been updated to Revision II :)  I added in a MOC3020 opto-triac driver and associated passives.  Hopefully the BTR24 will trigger properly now.  Also removed the ICSP header and added a 4pin serial header instead to make firmware updates easier. PCB size was increased a bit, designed to fit two on a 4x6 PCB blank.  Also replaced the screw headers with large holes and pads to solder the HV wiring to.  Should balance out the added costs of the MOC3020 and passives.

I'll try to get a PCB etched and populated tomorrow for testing.  Here goes round II!

Just a quick update.  I have not abandoned everyone following this project.  I have the second revision prototype design nearly complete, and the last part I was waiting for to show up from China (PCB toner transfer paper) should be hear today or tomorrow.  However, I will be pulling four grueling 12-14hr days out of town next week pulling and terminating 72 Cat6 drops and installing all of the Telco/network/server equipment for a new office location.  Oh yeah, and building the server room.  Why yes, I do mean building walls with a lockable door and a roof and AC vent, I do carpentry work too lol..... Then Mon/Tues the week after I will be migrating them onto our new domain.  So, while I have the design and the parts in hand, it may be a bit before I have time to etch and assemble prototype mark II.  I will try to get the schematic and PCB files updated to revision mark II this weekend before I leave though :)

While doing some testing (well, more like probing with a loose wire....), I successfully achieved catastrophic melt your retina high voltage electrical arcing failure!  I'll post a picture momentarily of the post short circuit PCB.  This is why you never probe high voltage circuits unless you are insulated from said high voltage.  Good thing I had the atMega out of it's socket at the time.....  Well, on to revision two.  I think I am going to revise the design to use a MOC2021 opto-triac trigger as I'm not having any success triggering the triac directly from the atMega, datasheet be damned.  I may even decide to throw in an H11AA1 for zero cross detection simply to reduce the code complexity a smidge.  The H11AA1 will give me an interrupt at each zero cross instead of every other one.  Still researching :)

Well, good thing first one was just a prototype.  I seem to be having an issue with actually firing the triac.  Still troubleshooting at this point, but I may end up having to either add a proper opto circuit to fire the triac, or switch to a random fire SSR (looking at cost differences before I decide).  While all the data I can find says I SHOULD be able to fire this particular gate sensitive triac directly from an MCU pin, I can't seem to actually get it to fire.  I can see the trigger signal and zero cross signal timing on my logic probe, but the triac does not appear to be latching on.  I've tried adjusting the timing, I've tried adjusting the trigger pulse width (up to about 200us), nothing seems to work.  Tried manually triggering the triac with 5V and 9V and still nothing.  Not sure what the issue is.  I will update again after I investigate some more.....

Just finished assembling the prototype.  Now to throw some test code on it and see if it works :)  That and figure out what I did with my hall sensor, I seemed to have misplaced it :(

I've uploaded pictures of the prototype PCB and updated the Eagle files to reflect the current prototype.  I'll have a new picture of the top of the PCB once I've done a toner transfer silk screen on it tomorrow morning.  More pictures and an update to come hopefully tomorrow after I get the components mounted :)

Broke out the drill press and got the holes drilled in the PCB this evening.  Should have it populated tomorrow so I can do some testing of the firmware :)

Well, I succeeded in etching the prototype PCB Wednesday night.  However, I had to make an emergency trip out of state for work and have not had a chance to get the holes drilled in the PCB or pickup the rest of the parts I need so I can assemble it and begin testing.  That should happen early this week.  I plan on drilling the PCB this afternoon and will post pictures once it's done.  As soon as I can get the components picked up, I'll get it assembled and start testing.

So, apparently the issue wasn't my printer, it was my heat source.  Things are working much better using a laminator rather than an iron.  First try with the laminator and magazine paper was about 95% successful.  Hopefully the second try will work :)