Category: Analog Electronics

Elecsys starts with a… Last Call?!?

Elecsys started out with what could have been a “bang”, but ended up being a “whimper”.  My “whimpering” from lack of sleep!

Two businessmen from the Riding Mountain area, Terry Ledoux and Rene Roncin, contacted Vansco about development of an remote controlled duck decoy animation system.  Vansco was too busy, so they referred them to Elecsys.

Terry Ledoux was a taxidermist based in McCreary MB, who sold his taxidermy business and went full time into being an outfitter and hunting guide.  He wanted his new product to be called Last Call, a trade name which he owned.

They had started the development, even had nice rotary moulded enclosures made, but they didn’t know how to do the electronics, so Elecsys took them on.

Elecsys was actually operating out of the attic of Jason’s house.  We brought in all our contacts on the job – mechanical development, PCB layout, PIC programming – and ran our credit to the limit to cover all the costs of parts, etc.

The last 48 hours were an absolute nightmare.  We worked non-stop, had all kinds of issues – not the least of which was destroying multiple radio modules – they were not only quite expensive, but we also only had so many to work with.  I so much needed sleep that I went downstairs to lay down on the couch, while one of my colleagues was going to try to commission another unit with our last radio module… when I had a flash of insight!  I had to rush back upstairs and stop them from powering it up!  The radios had been destroyed by inductive kickback from the motor drive circuit, which operated from the same supply.  We hastily reworked the circuit, and with another 14 hours of work, we delivered two functional prototypes to the customer for a business trip to demonstrate them to Cabela’s in the US.

In the meantime, we were all strapped for cash – the customer, Elecsys, Jason and I ourselves… and had to settle for only a portion of the planned amount.  We did cover our costs, but not much more.  Needless to say, the customer didn’t proceed with the next stage of the development, which would have cost a lot more money.  That was unfortunate, because it was a cool product with a cute name, and I think it would have been a winner.

Some time later, we sat around with Ed Van Humbeck and discussed our experience.  He shared with us that something similar happened to him in the early days of Vansco, and counselled us to always get as much as possible up front – to at least cover the bare costs of the project, should the final payment not be forthcoming.  We still had much to learn!

Development of Flex-Header Controller for Honey Bee

Brian Fletcher of Honey Bee had contacted Vansco to do a small electronic assembly for them, but Vansco was too large and busy, so they referred him to Elecsys.  We happily took on the task of creating a controller for their new 42 foot combine flex header.

The challenge is that, with a flexible cutterbar out front, you cannot rely on simple bumpers to keep the cuttterbar from interfering with the reel.  It might flex in the middle, coming up and cutting the plastic tines off of the reel.  Those little plastic tines are expensive and very time consuming to replace.

Honey Bee had created six flex points along the length of the cutterbar, where we placed rugged precision pots to measure the displacement of the cutterbar in that region.  We placed another precision pot on the reel arm.  We were able to calculate interference between the reel and cutterbar, and drive the hydraulics to move the reel up and out of the way.

Life isn’t that simple, though.  We needed to have controls in the cab, to configure the system and monitor its operation.  We created an in-cab controller with small display, rotary dial and pushbuttons, which communicated to the controller on the implement using CAN.  At each end, the processor used was a Microchip PIC18F series MCU.

Over the winter, we performed extensive static testing on a flex header using a portable hydraulic pump, at PAMI in Portage la Prairie.  In the spring, we travelled to Honey Bee in Frontier SK to visit the plant and perform more tests.  Over the summer, Honey Bee did extensive testing all over, and I attended testing in southern Manitoba, North Dakota, Minnesota, and Illinois, riding on the combine, watching the system operation, and tweaking the control programming.

An unexpected challenge arose, that of the hydraulic capacity of different combines.  It turns out that some manufacturers have a huge hydraulic operative capacity, and others quite weak.  It’s difficult to accommodate different manufacturers, even with different programming.

Another issue was the retrofit of the controls to the combine.  The hydraulic controls weren’t meant to be tinkered with.  On some systems, we could just drive the solenoids directly.  On others, we had to diode isolate our controls from the existing controls.  On others, the diode isolation set off alarms indicating open circuit on the solenoids.

It was going to be a long haul to make the system compatible with all the potential combine systems.  In the end, Honey Bee could not invest the capital to make a flexible enough system, and Elecsys could not make this investment either.  A further challenge was that the market for the aftermarket flex header that Honey Bee was making, would not bear the several-hundred-dollar premium for such a controller.

Sadly, the controller project ended with only a handful of (very nice looking) prototypes made.

Development of Ankle-Brachial-Index Measurement Proof of Concept for Koven

Paul Koven, founder of Koven Technology Canada, was dying, and wanted to see his dream of an automatic machine measuring the ankle-brachial-index of patients.  With a very short time frame, Elecsys was asked to create a proof of concept.

Elecsys produced that proof of concept in about 6 weeks, using an SBC running LINUX, four modified off-the-shelf blood pressure monitors (selected for their ability to be controlled and monitored through a serial port), and a 2 line x 24 character alpha display, and a few buttons.  The result was very large, heavy and not all that pretty – but it worked!  We provided a single unit, with rudimentary build documentation (as much as you can expect with a proof of concept!) and a manual, and they took it to St. Louis, MO to show to Mr. Koven.

Paul did see it before he died, and we got the feedback that it was much appreciated.

Koven’s management wanted to build more of the units, but were dismayed when they found out that it wasn’t a finished product.  They hounded us for months, asking for more construction details, drawings and blueprints, and alternate suppliers for the components.  Time and time again, we patiently explained to them that they had commissioned a proof-of-concept, not even a prototype, and that the each subsequent one would cost the same to build as the first.  We offered to put more engineering into the product to make it more polished and manufacturable, for a cost of course, but each time they declined.  Then, a couple of months later, they would contact us again about details on how to mass-produce the proof-of-concept.

S-PRO for Dorsey-Forbes Transmission Line

The T-PRO wasn’t warmly received, but engineers within the MAPP region noticed the flexibility of the platform.  There was a particularly challenging aspect of stability of the Dorsey-Forbes Transmission Line that could not be readily solved using conventional relays.  Minnesota Power (MNP) asked Dr. Swift if a better algorithm could be developed using the APT Relay.  It could, so Dr. Zhiying Zhang (who had graduated and now worked for us at Vansco) wrote the algorithm and it was installed at Forbes Substation.

Safe Power Supply Testing on TESLA 3000 MPB

One of the substantial changes for the TESLA 3000 was the incorporation of the DR2/TESLA power supply right onto the MPB.  The DR2/TESLA power supply was an amazing accomplishment, able to operate full power at reasonable efficiency from 38Vdc to 300Vdc.  A custom buck switchmode pre-regulator was used to bring the input voltage down into the range that a Lambda 48V half-brick DC-to-DC converter could handle – which was 36V to 72V nominal.  Below about 54V input, the pre-regulator would lock into full-on, passing through with minimal drop, giving optimal low end operation.

When testing the original DR2/TESLA power supply a decade earlier, we had an elaborate procedure that required a sequential voltage bump, checking critical operation parameters as the test proceeded.  For instance, first going to a low voltage just above where the pre-regulator would start switching, and verifying that it was switching at the proper frequency, and that the output voltage was reasonable and within range.  Without ensuring that the pre-regulator was working properly, a high voltage pass-through would destroy not only the DC-to-DC converter, but also the large reservoir capacitors that we had at its input.  In fact, the reservoir capacitors were dangerous, exploding when overstressed!

Somewhere along the way, the cautious approach was forgotten.  The contract manufacturer making the TESLA 3000 MPBs was experiencing explosive failures in testing.  Their staff was afraid of the board.  They would put a box over the board before testing.

Elecsys put its experience with GPIB to good use.  We obtained more GPIB equipment and a Xantrex XHR300-3.5 power supply, which had a serial interface.  I wrote the first draft of a PERL program to direct the fully automated testing of the TESLA 3000 MPB power supply, then had Nishant Dhruve complete the work.

Production Support and Test of TESLA 3000 AIB using GPIB

After performing the design and full verification of the TESLA 3000 AIB, Elecsys was asked to support the manufacture of the boards at Trilogy-Net in Calgary.  There were challenges in getting the boards to work, mostly because of the silly little LM358BP, which is in a tiny 8 microbump package.  We had process issues on getting it to solder properly.

In the end, the fault was the layout that I had supervised.  Unfortunately, in our desire to pack everything onto one side of the board, I had moved down to the absolute smallest package of the LM358 dual op-amp.  Well, in the end the board layout person went to double sided assembly but didn’t tell me until the last minute, meaning that the tiny op-amp stayed.  There were larger parts around the op-amp that drew the heat out of the oven, so the op-amp wouldn’t solder consistently.  This was a headache until a couple of years ago, when that op-amp was finally replaced by the larger SOIC version.  Sigh.

Anyway, we wanted to do a 100% test of the AIBs to ensure proper function before TESLA assembly.

I acquired a number of surplus IEEE-488 / GPIB test equipment and a PC GPIB card, and wrote scripts in PERL to control the test equipment.  We were able to drive precise voltages into each channel, to test offset and gain, then certain frequency signals to test filter response.  Data was logged, analyzed, then the aggregate data was reviewed continually to calculate statistical process control.