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Multifunction Microprocessor Control and Regulation of Power

As I get more and more used to analog control of power giving way to digital control, I often look for applications where the microprocessor is controlling the entire show. I do this for several reasons, the first of which is because I am interested in where the market is going as products gain more and more intelligence. Secondly, I have a desire to incorporate as many control features as I can into a testbed electric vehicle I am developing. I want to have a power supply, battery charger and status monitor, peripheral[s] controller, and motor controller all designed into a single control block. I saved motor control for the end of that sentence because this is a blog about controlling power and not just a power supply.

If I were to choose a design based on a single controller, I might be able to use only one software program instead of having to learn new ones every time I found a processor with a specialized function. Furthermore, the testbed electric vehicle that I’m making needs to be able to transmit communications over thirty feet which makes wireless Bluetooth questionable. I need the alternatives of another wireless communication link in addition to a wired connection such as USB or Ethernet as a second alternative. It would be nice if the controller accommodated multiple protocols.

My testbed is my monster truck Go-Kart that I want to electrify for indoor use. The ultimate goal is to drive up bedside to a hospitalized child thus overcoming their limitations of being restricted to indoor activities. Nothing breaks my heart more than a child that can’t run and play with the others. This is my way of breaking that barrier by bringing a coveted outdoor item indoors. Beyond that, I’m building a performing and ride platform that includes the train ride towed by the monster truck. I have to interject here that the performing part is for parades when my riders are stuffed animals and not when children are riding in the towed train cars. I do plan to build a train car that accommodates a wheel chair in hopes that I can also give rides to children with limited mobility.

This project is the culmination of my engineering experience and education as I get to combine electrical propulsion, battery charging, voltage transitions, and electric four-wheel steering into the electronics as well as the programming the control of these functions into a microprocessor. I get to put many of the modern goodies [LED’s, lighting control, Bluetooth, Android Apps, WiFi signaling, USB, etc.] into the design while expanding my knowledge in these areas. I’m lucky to have a combination hobby and testbed enabling this lab experiment that could someday benefit children.

One other functions of this vehicle is to provide valuable lessons through books I wrote. Next to soothing sick children, my other passion is to help children avoid brain injuries by wearing a helmet. I see so many kids that ignore head protection because helmets aren’t cool or are uncomfortable. Well, so is sipping steak through a straw as two young men on scooters put it one day when stopping to admire the monster truck. Hats off to these two who were wearing their helmets. Actually it’s more like hats off, helmets on. I hope a bright yellow monster truck will help to convince more children to be like them and wear a helmet. Life as an analog engineer is applicable to this beneficial cause which again, makes me feel very fortunate.

Some of the innovations I am designing may be of military use for autonomous battlefields. Therefore, I keep an eye on the military SBIR, Small Business Innovative Research, grants as a method of funding the effort. Otherwise, it’s pretty much out of pocket which means slow development yet I’m also not held hostage to investors.

That’s enough about the testbed. I introduced it because of the enormity of the control it will take to achieve a safe and reliable design. I talked a bit about the funding because in each of us, there is that spirit to invent that nobody cares to fund which results in having to go it alone. It’s a wonder how many good ideas never made it to market because of a lack of funding. On the other hand, funding through DARPA and SBIRs has proven to bring ideas into reality. As I uncover the sources for technology and funding, I share them in hopes that the readers of this blog can follow their dreams. The blog now focuses on a similar design that has multi-functional control and also has me quite intrigued with the amount of functions and control going through a single microprocessor.

With the amount of information available on the Internet, I’m often finding that some of my development work has been done already which saves me valuable time. Because a lot of hobbyists read Planet Analog, I try to pass along tidbits that I find so as to save my audience time and effort. In my search of power systems with master controllers, I came across an exceptional power supply for electric door locks that performs a number of functions using a single controller in a manner similar to my desire for an electric vehicle.

Figure 1

NU2 Power Supply with a Single Controller and a Display Screen

NU2 Power Supply with a Single Controller and a Display Screen

The NU2 Smart Uninterruptible Power Supply1 alone is quite impressive as it regulates power, records load data and provides over current protection, is powered by and can charge a battery or two batteries in series, and checks for reverse polarity on the input as well as output with auto recovery while avoiding any damage to the system. If that isn’t impressive enough, the system also displays many of the parameters and the status of the outputs, inputs, and vital door lock alarms all on a 2.4” color LCD display. For those of us with only two arms, this little gem of a feature negates the need for having to use test probes while holding a measurement meter. Even the display is touch free as a simple swiping hand gesture allows scrolling through screens. For those millennials that need to exercise their thumbs, there is a Bluetooth phone application for programming the system.

Because this particular power supply operates off the common door lock power of 12V and 24V, I’m itching to get my hands on one for my little project that will run off Lead-acid automotive batteries of a similar voltage level in the beginning. Later on, I might have to go to the more advanced battery chemistries and related voltage levels for the energy density advantages. I really don’t value being upside down in a lead-acid based electric monster truck with acid pouring all over me which along with the higher prices of gel cell lead-acid batteries prices has me looking at alternative chemistries with more favorable behavior while upside down. Easy parents, that’s the performance version of the monster truck, not the slower version I will use to tow children or enter parades with.

Amazingly, there is one aspect of my monster truck train ride that this power supply really has me lit up about, hand gesture control of display screens. Although I have rear view mirrors on my truck for viewing children in five different train cars, that are soon to expand to ten, it is not an easy task especially when the train snakes out of view of the mirror. Couple the limited view with the task of steering two axles so that I can crab sideways and the result is that my hands being quite busy with no time to scroll screens through a touch interface. I’m sure many can identify with a lost Kodak moment due to latency in phone screens in a similar manner. It would be advantages to scroll screens with a quick gesture of the hand than to rig up and attempt to focus on five to ten screens in my vehicle while driving.

Figure 2

A Hand Gesture Controlled Display Would Enhance My Limited Rear View of the Train Cars

A Hand Gesture Controlled Display Would Enhance My Limited Rear View of the Train Cars

The NU2 Smart Uninterruptible Power Supply1 uses Ethernet and RS-485 communication in addition to Bluetooth. I am interested in these alternate forms of communication especially due to the length of my train cars exceeding the thirty foot signal range of Bluetooth capability. Again, one controller is capable of all of these protocols in the NU2 power supply thus making it easier to design into my application. There are other features in the NU2 power supply such as load current monitoring and regulation that hobbyists may find of use. I’ll leave that to another blog.

It’s said that men are just boys with bigger toys. I can’t really argue with that especially since a Go-Kart that once entertained my children is slowly becoming a testbed for developing and testing new ideas as well as a home for sharing advanced technology through Planet Analog. As I stumble across multi-functional technologies with the advancements I can incorporate, I save a lot of time and edge closer to completion. What’s not to like about that?

No stuffed animals were harmed during the writing of this blog.

References

1 NU2 Smart Uninterruptible Power Supply website

1 comment on “Multifunction Microprocessor Control and Regulation of Power

  1. ThomasMaloney
    September 20, 2018

    It is not difficult for us to get hold of technological advances that can help us gain that extra power we need. A small device is already able to hold so much power that we do not need to look any further to run heavy load setups. We just have to know exactly the layout we would like to build and roughly how much energy is required to power up the setup. Previously, we could be needing more than just a single power source, but as time passes us by, our lives have been made much simpler. We ought to be thankful for various industry players who have played a fair share in introducing new tech devices to everyone.

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