1983 D.C. Johnson FAC-1 Revision C

This is a 1983 D.C. Johnson FAC-1 Revision C. It works like new with just few minor repairs. That’s 30 years in service and now ready for many more. Not bad!

The D.C. Johnson FAC-1 is an Air/Fuel control unit similar in function to the OEM “Lambda Controller” units for European cars equipped with mechanical fuel injection systems. It was designed to retrofit cars made for sale in the European market before emissions regulations were instituted, to meet United States specifications after they were imported into the United States of America.

Finding the Right 3D Printer

Engineer LLC will be investing in it’s first 3d Printer shortly, so we have been shopping the web for the best candidate(s). There are an number of options for the low cost (relatively) reprap based designs available. Ranging from scratch build with used parts to ready to print fully assembled units. Here’s a sampling of what I have found on the ‘net so far.

Start here with a good video synopsis of the low end of build it yourself to kit range by Neil Underwood… Still Extruding: RepRap Price Points

PrintrBot is an interesting newer product line of supplies, parts and kits. With the commendable goals of bringing the cost of entry even lower and making kit assembly simpler for beginners. This venture was launched via what appears to be the most successful Kickstarter technology campaign to date…

There are quite a few vendors popping up with offerings in the mid range with kits and some with fully assembled products such as PrintrBot listed above.

And then there’s the Granddaddy of all commercially available derivatives of the open source “reprap machine” with a Geriatric 3 years in existence… “Makerbot Industries

For our first unit, we will likely be going with the Makerbot Replicator MK8 with the dual extruder option. This one comes fully assembled and features the all important dual extruder to allow for deposition of water soluble support material. When support material deposition is available, the printer is no longer limited to making only objects that are self supporting during build. This makes the unit more competitive with much more expensive “Mainstream” FDM printers.

The 3D Printing Revolution

It seems that the 3D printing bug may be spreading to Engineer LLC. There is a growing wave of enthusiasm for low cost (relatively) 3D printers, particularly in the Fused Deposition Modeling (FDM) category. FDM is a process that uses a plastic Filament fed through a heated extruder head to print a model from a 3D CAD rendering. It’s really amazing how the capability of these printers has improved while the cost of entry has also come way down. The new developments have been spurred in large part by the open source project “reprap”. Learn more about how it got started here.


HV Analog Isolator/Scaler

In EV electronics, the Electrical Storage System (ESS) is typically isolated from the lower voltage system for lighting and accessories. In many installations this creates a need for isolated signal conditioning for ESS instrumentation when that instrumentation is powered by the low voltage system.  I found an off the shelf “Demo Board” for the Analog Devices AD7400A Isolated Sigma-Delta Modulator that made it quick and easy to build up an Isolator/Scaler module for monitoring the ESS with a 0-500V range.  The output is compatible with the 3.3v range of the custom control module on a prototype vehicle that is currently under test.

HV Analog Isolator/Scaler

The HV input and 12v power source are fused for protection. The HV input is divided to yield a 0-320mv range at the input of the AD7400A. The output produces a fully isolated and scaled voltage of 1.65 to 3.3v that is linear (difficult to achieve with more common optical isolator circuits). The output is essentially an isolated and 5X amplified version of the 0 to 320mv input with a floor of 1.65v This equates to an ~1.65v range on the output (0.320 X 5).

For more detail on how the AD7400A and support circuits work on the Demo Board, see Analog Devices Circuit Note # CN0185.

January 2012. A new beginning

With a Prosperous 2011 drawing to a close, I began the process of forming a new Business Venture “Engineer LLC“.  With a portion of my earnings from Contract work, I have formed a new LLC organization to serve as a foundation for the several business ventures that I have been incubating or planning over the course of 2011.  Engineer LLC is now operational and forms the new “Parent” organization for several business ventures…

    • Spidersource Unlimited is my vision for a provider of Consumer and Technical Software in the mobile marketplace. It has yet to be officially launched as of this writing.
    • dc-johnson.com was created in January of 2008 in response to an inquiry by a Ferrari restorer and as a tribute to my Father’s invention of aftermarket emission control devices for the Automotive “Grey Market” of the United States in the early 1980s. The site serves as a source of information for owners of these now antique Automobiles. Occasionally, a request comes in for assistance to this site which will now be a division of Engineer LLC.
    • Vernon Johnson Engineering Services has been consulting with private Inventors since 2004 to assist in bringing new inventions to life! Vernon Johnson Engineering Services also occasionally provides Advanced level Computer Networking and Systems Engineering services to Clients with challenging Computer needs.  For the time being, Vernon Johnson Engineering Services will remain independent for existing Consulting contracts.  New Consulting contracts will be fulfilled through Engineer LLC.

There may be other ventures in the future that will emerge as projects or ventures of Engineer LLC as well.

The new web presence for Engineer LLC is hosted by Dreamhost. I have been using them for 7 years (ever since I started publishing public web content) and must say I am a very satisfied customer. This blog you are reading right now is hosted on Dreamhost. If you are considering opening a new web Hosting account, I strongly recommend Dreamhost. Should you choose to use their services, use the promo code NEWUSER2012 and you will get an additional discount when you create a new account with Dreamhost. Full Disclosure: I do receive a small referral fee for referring new customers.

Vernon Johnson

January 24, 2012