Sunday, July 28, 2013

Just a quick note

Over the past week I installed the regulator aboard Viking Star, and have made three runs.  Two long and one with lots of starts / stops.   I have been working through issues, but still have a few to go before I can declare it has a basic level of functionality.  I am facing two right now:

  1. During startup, when I release the main engine starter button, the regulator faults  with INA-220 I2C read errors.  They are random in nature, but directly associated with the releasing of the starting button.
  2. When running with the Arduino regulator, I seem to under-read the battery voltage.  When I switch back to the standard fixed voltage regulator, the Arduino regulator correctly reports the voltage.

Both of these are making me think there might be something with how I have installed the regulator.  It is complicated in that I left the original regulator in place so I can switch back and forth easily.  But I am wondering if there is a ground loop that is causing coupling of the starter as well as loading on the line during running (causing a voltage drop, and hence under-reading of the battery voltage).   I just need to get down in the engine room with some meters and/or O-Scope, but have been working instead on the DC Generator / Watermaker as we started using the watermaker for the 1st time after installing the integrated controller / regulator...

Hopefully will get some time next week to make  progress.

ps:  some may have noticed I snuck in rev 0.0.2 of the source code, and its associated .wrd file describing the ASCII interface.  I did that to support the person who is working on a GUI for smart phones and such.  Figured it would be better for him to use the latest ASCII syntax while developing, and the code will still work in a kind of 'demo mode' on a standard Arduino as long as the "#define TESTING"  is enabled.

Friday, July 19, 2013

1st unit ready to test out!

It has been very quiet on this blog for some time now, mostly as a result of Kristi and I taking a trip back to Minnesota for her folks 60th anniversary, combined with boat travel to and from the Seattle area.  But we are back in Canada now, and I have just about finished up with the 1st build.

Top view.
Field connectors are the large ones on the top left, bottom left connects
battery voltage sensing, Alternator stator, as well as engine 'enable' line.
Top right has Feature in/out connectors and Alternator shunt, while
the bottom right has the block of RJ-45 connectors for temp probes,
service probe, and synchronization cable for twin engine install.

Bluetooth module is top center.

Bottom view.   Field Driver FETs (right hand side) will mount face down onto
the heatsink, with relief holes in the PCB to gain access to the mounting screws.
Need to use a bit more PCB cleaner to get rid of the remaining residue.

Today I did some mocking up of the assembly, just to see what parts fit and what I was missing.  Mostly it looks good, but I will need to get taller standoffs to raise the ‘cover’ up some more (Cover not shown here).

All mounted.  I need to purchase taller standoffs to support a small plastic cover
which will go over the whole unit giving it a nicer finished look, and some additional
protection beyond the conformal coating.

Also need to print up and add the stick-on labels describing the DIP switch and connectors.

A few issues I have found:  There was one design error in the FET driver, the 15v clipping zener needed to go between G and S, not G and GND.  I relocated the Zener to the back of the PCB and tacked it on.   I also am finding the NTC daughter boards a real PITA to solder up.  Partly due to their small size, partly due to I made the wire through holes a little small, and partly due to the Chinese sourced CAT-5 cables I purchased, which seem to be made from Aluminum – not copper…  Digging through our parts stash I found some unused Magnum remote cables and use them.

REALLY small PCB there, that is a CAT-5 cable coming in from the left...

And here is a photo of the 'Service Cable'.  This is used in conjunction with the Arduino programming environment to upload the Firmware to the regulator.  It can also be used to send/receive ASCII commands to existing firmware to program some of the configurable features, for those who do not wish to mess with 'C' programming, nor the Bluetooth interface:
Optional Service Cable.

My next step is to complete the mounting and then install it on Viking Star.  I am very interested to see how some of the new algorithms work (specifically the auto-alternator size determination).   I figure I will also want to wire up a remote ‘kill switch’, just in case things go really bad.  But as with the integrated Engine control / regulator project, I will be making several test runs, logging data, and making adjustments to the source.   I am not worried about the core regulator functions, it is the new stuff placed around that that I need to check out.