InCircuits, Inc.

Chronological Career History

The following is a chronological description of the career history for Steven R. Stadler ( This would be a good time for a fresh cup of coffee )

Honeywell (1984 - 1989)

During undergraduate college at Michigan Technological University, I was offered a Co-Op position at Honeywell Defense Systems Division - Ground Vehicle Electronics group in Hopkins Minnesota. This was a tremendous opportunity where I learned so much about the engineering process for developing products. It was all "hands on" designing, laboratory testing, field testing and collecting data, writing assembly language code, using In Circuit Emulators and lots of other really expensive equipment. This place was like the Disney World of engineering!! I worked two six month Co-Op sessions in this group, the Ground Vehicle Electronics group I was in had moved to the Shady Oak building for my second session.

I graduated from Michigan Technological University, and was offered a full time position at Honeywell Defense Systems Division - Ground Vehicle Electronics group, which was now located in the Bren Road building, your desk never stayed in the same place for more than a year at this company with all of the expanding and contracting that was going on at that time. During the next six years there, I worked on many, many projects, expanding my engineering knowledge and capabilities further with each one. The first project I worked on, was the navigation processor CPU module for the Egyptian Land Navigation System, which used a moving mass gyroscope and accelerometers for inertial navigation. We started the project using the Intel 8086uP, but before the project ended, we were able to upgrade to the 80186uP, and there was a math co-processor too!! Yep, that was a long time ago. We used an ICE system that had several interface cards with a zillion wires attached to the pins of the processor and memory and peripherals, and you could watch the timing at various triggering events that would be set up. It was cool!! I was writing the assembly language programming that would exercise the hardware to make sure everything was connected and functioning properly so that the software group could have a working platform to run the product software. My friend in production engineering told me that this CPU Unit went from development to production with no changes that needed to be made, and there were no failures up that date, which was probably less than a year into production.

My next project was working on a system that was a countermeasure against magnetically fused land mines, VEMASID. My part of the project was to develop a test system that would simulate several different types of magnetically fused land mines. This project was quite challenging and I learned several things about analog circuit design, frequency response and filtering, low noise power supply design, low noise pcb layout, A/D conversion, more embedded assembly language coding, high voltage switching power supply design, as well as low noise power distribution between components of the system. I also learned very much about team dynamics and the importance of proper documentation of test results and changes as they are being made. Another role I had on this project was mentoring another engineer who was designing the CPU unit for the countermeasure system. The CPU module was very similar to the one I had developed on my last project, so I was able to share much of what I had learned.

Alliant Techsystems (1989 - 1992)

Shortly after that, Honeywell spun off it's Defense Systems Division to become Alliant Techsystems. While at this company, I mainly worked on the STAFF project. STAFF was a warhead that was shot out of a 155mm cannon, and used radar to search for a tank. This round was to be shot over the target, and while the round was approaching the target, it would roll using steering jets of solid propellant exhaust gas, which would aim the shape charge warhead which was on the side of the round, at the top of the tank, and when the round was at the point where the tank was positioned perpendicular to the trajectory of the round, the warhead would fire, and the tank would be destroyed. For this project I developed the Digital Signal Processor board, which used a Texas Instruments DSP (this was a real time system that had to be really fast for a short amount of time), and several of the peripheral control circuits, including the electronics that controlled the steering of the round, and the fire control electronics. In the development phase, we used FPGA's and the DSP chip to implement the design, while others were working on putting the design into an ASIC. After the ASIC designers had all the information they needed from the breadboard hardware, it was time to move on to a new company.

Holaday Industries (1992 - 2002) ( This would be a good time for another fresh cup of coffee )

Holaday Industries was a small company ( I say was, because Holaday Industries was bought by ETS-Lindgren, dissolved and absorbed with the operations moved to Austin Texas ). There were 28 people working there. It was quiet compared to all the hustle and bustle at Alliant Techsystems. Engineering consisted of the engineering manager, who also did engineering, and the mechanical guy, and the pcb layout guy, and the ham radio guy, and the technician.

My first project was to make an Isotropic VLF Magnetic Field Meter, the HI-3637 . The dynamic range was quite large, and the maximum field it was to measure was quite large, and the electronics would be in close proximity to these large fields that were to be measured. Designing the circuitry was straight forward, and we used a PIC micro-controller, so the programming was relatively straight forward. However, the circuit board layout and shielding turned out to be quite challenging in order to have the measurement circuit operate while immersed in the field it is supposed to be measuring. After a few iterations and lots of testing, we came up with something that worked very well.

My next project was to make a low frequency ELF / VLF Electric Field Meter, the HI-3638 ,that was to be designed so that it could be used for testing according to the Swedish MPR and the IEEE 1140 test requirements with full ELF and VLF capability in a single meter. The analog front end of this circuit turned out to be very interesting and worked very well. This unit uses a Motorola micro-controller, and is isolated from the readout via fiber optics. This is where I began learning about fiber optic communication and the circuitry that makes it work.

My next project as to make an Induced Current Meter, the HI-3702 . This product operates well into the intermediate frequency range where the circuit board layout is critical to the frequency response of the system. This product uses a thermally based true RMS converter which resulted in fabulous accuracy over the dynamic range. The frequency response from 9kHz to 110 MHz covers the major part of ANSI/IEEE C95.1-1999 frequency range. The 2 to 1000 milliamps range covers the full C95.1 requirement with 10X over range capability for extreme measurement situations. The HI-3702 also meets the ENV 501662 European Pre standard for Human Exposure to EMF.

Each of the above products had unique low noise power supply designs, using different configurations of battery packs. I began developing smart peak chargers for each of the products, because people were ruining the battery packs using the trickle chargers that were previously supplied with the meters.

I then developed what turned out to be the flagship probe for Holaday Industries, the HI-6005 Electric Field Probe. With the help of my colleagues, Jay who developed an excellent antenna and RF section, and Dave and Dale who made the folded flexible pcb design possible, we were able to develop a product that brought a new way of thinking into the probe field measurement world. If you think you can handle another cup of coffee, here is the patent that describes the design of this product. This is the product where I began using the Atmel line of AVR micro-controllers. The goal was to make this probe as small as possible, so the electronics needed to be very low power so that the battery pack could be very small. The Atmel AVR Micro was a good choice for this application. We had custom fiber optic assemblies made in order to reduce the size as well. Each of the three axis are instrumented independently, and simultaneously clocked in order to achieve higher accuracy by making the measurement of each axis at the exact same time. This product uses gas gauging to indicate the battery charge available, and has a temperature chip in order to indicate if the measurement circuitry is out of the temperature range for calibrated measurements to be accurate. We were challenged with many obstacles with this project, but we found solutions to all of them and developed an excellent product.

After this project was completed I was working on a new readout, the HI-4460, and this is when ETS-Lindgren purchased Holaday Industries, and moved the operations to Austin Texas. Everyone at Holaday Industries was offered a position at ETS-Lindgren, if you were willing to move to Texas.

InCircuits, Inc. (2002 - present)

I decided to stay in Minnesota and make a new business as an independent consultant. Fortunately, ETS-Lindgren was my first client. There was still work to be done in the world of field measurement electronics.

One of my most significant projects for ETS-Lindgren was to develop the new flagship probe of the Holaday line of probes for ETS-Lindgren, the HI-6105 as well as the laser control unit, for this probe is similar to the HI-6005 above, except that is has no battery!! It is powered via a laser over the optical fiber interface. This was an idea of mine, and I proposed this to ETS-Lindgren, and they were excited about the idea. Developing the laser controller was very interesting and there were many new obstacles to overcome, and we succeeded in making another excellent product. The laser is modulated in order to accommodate communication to the probe, and the laser power level is adjusted using a closed loop system, where the probe communicates the output voltage of the photovoltaic converter to the controller, and the controller adjusts the laser power for optimal performance. There is also a safety interlock system in order to shut down the laser in case the optical fiber is disconnected during operation, or prevent the laser from turning on if the optical fiber is not connected and the system is turned on.

Photonic Power saw what I was doing for ETS-Lindgren, since they were making one of the components, and asked me if I could work on the development of a proof of concept for them. They wanted to power a GPS unit using laser power over optical fiber in order to collect time stamping information from the GPS system. This is where I gained experience using GPS chip sets.

A friend of mine who is an application engineer for AMI Semiconductor asked me if I could make a demo board that could be used to demonstrate the functionality of some of their industrial chips. This board demonstrated their I2C micro stepping motor driver chip, high power LED driver /relay Octal High Side Driver chip, EEPROM, 16-bit Sigma-Delta ADC, and a custom 8051 based micro controller.

The first project I worked on with Waterstrike Marine was to develop a speedometer calibrator for S&S Cycle ( click on electronics and engine controls, and go to page 11 ). S&S Cycle has been testing one of these continuously for several years, and last I heard, it has still not failed. We have also been developing instrumentation for the Naturevision AquaVu and WellVu lines of products, adding temperature, depth, and compassing measurement capability and using video overlay circuitry to display the data to the user. The Motorized AquaVu product has a high current buck-boost switching power supply and motor controller circuitry. We have also developed proof of concept units that use a wireless data link and operates using very low power, such that the battery life will be over ten years.

I have done work with a medical startup company where their product would apply electronic signals to tissue, and the applied signal was required to maintain charge balance per a standard. I developed a specialized interface circuit that provided synthetic tissue parameters and instrumentation circuitry to supply the measurement signal to a Linear Technology 24 bit Delta-Sigma ADC. With a noise floor of less than 4ppm, we were able to achieve very accurate measurements.