Friday, May 25, 2012


Last night I lost a friend.

Tom Emmons, friend for 31 years, engineer, inventor and colleague passed away. Tom was one of those gifted engineers who could visualize the actual flow of electons and fields. Whether it was a high current PCB layout or the solution to an EMI problem, Tom's work was a true work of art.

Beyond that, Tom was a true friend. Always there, whether it was a technical problem to bounce off him or just getting together to let off steam. Always ready to help, even if it meant flying halfway across the country.

I met Tom at a little starup named CPT back in '81. Since then we worked together at Datacard in the late '80's, Aria Corporation in the mid '90's and just recently on some truly breakthrough aerospace technology. Over countless meetings and lab sessions we hammerd out solutions to a variety of engineering and other problems.

Rest well, friend.

Tuesday, May 22, 2012

Cutting the Power Cord

Cordless versions of small electric tools have been around for some time.  As discussed in my previous post, battery improvements and a "clean sheet of paper" design approach have led to significant progress in this area. However, there are power levels where the combination of battery power/ size/ cost just isn't there to make a direct battery version of a product practical. Today these applications are still only available as grid connected devices yet many of these applications are already electronicly controlled.  

What if we could cut the cord on these applications without changing the existing product at all? The answer is that we can by providing electronics to boost the voltage to grid levels.

This isn't a particularly new concept. One often used approach is to install a DC TO AC inverter between the battery and the product. The output of the inverter mimics the 50 or 60 HZ power line at 120 or 220 voltc AC. However, unless the load is an induction motor or has a 50/60 HZ transformer, this approach is ineffecient, unnecessarily costly and electrically noisy.

A better way is to take advantage of the fact that most grid operated electronically controlled systems first rectify the incoming AC to DC. So converting the low battery DC to high voltage DC works.  Put the DCDC converter near the battery, and the wires to the application need be no bigger than their AC counterpart. Size the battery to the mission and the battery size and weight are minimized. Since the DCDC converter can be smart, it can accurately meter battery power and provide an excellent level of safety. All without changing the design of the end product..

At Software Defined Power our DSP controlled DCDC technology can be scaled from peak power levels of a few watts to 5KW and above with effeciences better than 94% and power densities of  16W/cubic inch.

This technology opens all kinds of options for product and system portability. and we love brainstorming options with our clients, so call or drop us an email and start thinking "what if". 

Thursday, May 10, 2012

Rethinking small gas engines

It's spring here in Minnesota, when everyone emerges from their houses and hits the neighborhood trails, yards and parks. The air is filled with the sounds of birds and the whir of small gas engines.

At Software Defined Power we operate much like an architecture firm, but instead of developing or redeveloping open space, we engineer or re-engineer motion. One area is re engineering off grid motion systems that are powered by alternative energy systems, such as solar or wind. But how about all those small gas engine applications?

The emphasis on electric and hybrid propulsion for vehicles over the last few years has yielded significant improvements in battery technology. Now these improved batteries can be put to work replacing small gas engines. But to do the job right requires a system approach. It can't be done with components from a catalog. The cordless tool manufacturers realized this and designed their tools from the ground up. The battery packs, chargers, motors and mechanical systems are all designed to work together to accomplish a mission, which may be to drive all the screws in the construction of a deck. New system level concepts needed to be worked out. For example, continuous service life can be achieved by sizing the battery for both a reasonable mission life and a fast recharge time, then including two batteries and the charger in the system.  Another is designing everything downstream of the battery (controller, motor, linkage, etc) for maximum efficiency, which extends battery life.

Again, the cordless tool manufactures have done a good job of this, but those are low power applications; a few hundred watts at best. At Software Defined Power, we have the technology to push the cordless power limit to 4KW and beyond, This can turn any application that uses a 5HP gas engine or smaller into a cordless app. Not only producing a greener product, but a smarter one.

For this and more ideas of what Software Defined Power can do for products, check out our website