Tag Archives: electric vehicles

Perfect Storm

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Propane powered windmills protect vineyards and orchards

Weather events like the recent storms that caused the recent power outages in Texas, show the limits of our electric power system. The current power interconnect grind is only able to carry 5% of the power that we use. This means that the power you use is generated locally. When a town like Houston is hit with a cold weather event that causes a spike in electric demand a 5% capacity interconnect grid will not save them. This is why you see propane powered frost protection in more northern areas. They will work when an ice storm kills power from the grid. Electrically heated hot houses like you see in Texas are doomed to not provide protection when a winter storm descends.

local electric storage will be a part of every electric refueling station

.We wish to double the amount of electric power we wish to purchase from our electric power grid to power electric vehicles. While this is a good thing for climate change, it causes other problems. Currently the pipe line system delivers the lions share of the vehicle fuel we use. Each gas stations stores a few days supply. An electric grid that currently only carries 5% of what we use will be severely overtaxed if we double our usage. Beyond that no one wants a high tension transmission line in their back yard. The near term solutions will involve continuously transmitting at capacity by adding energy storage at both ends. Home vehicle recharging equipment will simply not work when the grid is overstressed to the dismay of individual users.

Alloy

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New alloys underpin innovative automobiles

In the heyday of Detroit, popular cars like a 57 Chevy included a die cast aluminum alloy automatic transmissions. Success leads to wide spead adoption. The aluminum alloy used to make the automatic transmission became the world standard. Die cast aluminum alloy became a commodity listed on the London Metal exchange. The purchasers of 57 Chevy .autos enjoyed the advancement. This is similar to the improvement in human lives that became possible with the creation of metal alloys for making a surgical scalpel. Time marches on. Today, we would not consider using anything but a scalpel made of the best surgical steel alloy. The buying public feel the same way about thier automobiles. The enthusiasic public acceptance of electric automobiles are causing new aluminum die cast alloys to displace the old standards. The brittle corrosion prone old standards are being replaced with ductile aluminum die cast alloys that are strong without heat treat.

Self Imposed Limitations

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We all enthusiastically adopted hair dryers when they were introduced. The early version were 1200 and 1500 watt. The manufacturers of the time self imposed this maximum power. They collectively believed that a 110VAC outlet in a typical North American home could only deliver this amount of power. The market has progressed past this self imposed limitation. I was looking at the 1875 watt dryer that my wife stores on the bathroom counter. I reflected that it seems ages ago that we dried our hair at the slow rate of a 1200 watt hair dryer. On the other hand, it could be argued that the relentless conversion of fuses to circuit breakers has reduced the inconvenience associated with overloading a plug and blowing a fuse.

Other good examples of self imposed limitation is the 4 minute mile. When Roger Bannister determined how to run a four minute mile, he accomplished the feat against a background of all the other suitably conditioned athletes believing it was impossible. A good example of a self imposed limitation. Today most top runners break the 4 minute barrier in competitions. They are unaware of the historic self imposed limitation. It is easy to identify self imposed limitations after they are exposed.
Discussing self imposed limitations is more useful when the participating parties realize that it is possible to obtain greater benefits by abandoning them. Inventors and start-up companies run into this artificial barrier all the time. Amid my current projects is a new technology battery that is designed to be rapidly charged. The stodgy users have to be taught that they can charge this battery when ever it is near a 110VAC outlet. It is no longer necessary to wait unit the battery is completely discharged to restore some charge (a self imposed limitation) Harder to understand is a reluctance on the part of the engineers who design the charging system to switch gears. They insist on retaining a self imposed limitation. The charger design engineers need to be taught that a short (opportunity) battery charging higher output burst will not overheat the charger. This improvement only occurs by abandoning the self imposed limitation, Yes the charger can deliver a short duration burst of amperage which is greater than the amount it can continuously deliver over a long period. Just like the the hair dryer manufactures, battery charger manufacturers eventually will adopt enhanced opportunity charging performance. It will take a “Roger Bannister” to see beyond the self imposed barrier blocking higher power outputs

Hall Effect

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Aurora lights show the magnetism that surrounds us

Magnetism remained mostly a mystery until the modern centuries. Unlike lightning that can’t be missed, especially if the strike is close by, Magnetism in nature only shows in the aurora and magnetic compasses. Edwin Hall experimented at the end of the 18th century and discovered that a magnetic field could change the path of charged particles. The aurora is a vivid example of the earth’s magnetic field changing the path of charged particles streaming from the sun. This discovery remained a scientific curiosity until the advent of semiconductor electronics made it possible to put the discovery into use.
The gasoline powered automobile was an out-growth of the steam engines of the time. It was not surprising that the earliest automobiles had very primitive electrical devices. The model T used a spark coil with a buzzer to sent ignition pulses to the spark plugs. The driver was tasked with also operating a lever on the steering wheel to select the required spark advance. Certainly not the user invisible electronic spark advance built into just about every car in use today. Replacing the electric “points” in this design of ignition was part of the regular tune up that all cars prior to 1978 required. A magnetically coupled hall effect sensor was the answer. The magnetic field within the sensor can penetrate through a water and air-tight barrier around the electronics. This tight barrier separated the electronics from the corrosive outside environment. Cars no longer required regular replacement of “points” and the corner gas station garage became a convenience store.
A reliable sensor was only one part of the total solution. Smarter computer programs were also invented to work with the sensor and used to insure that the spark plugs only fired under the correct conditions. The computer programs that run the ignition from the hall effect sensors input have become very smart. The programs accomplish everything from backfire prevention, emission reduction, fuel economy improvement, and smooth gear shifting.
Electric vehicles have been around for a long time. In the early days of the automobile
Electric cars like the Detroit brand shown vied with gasoline powered vehicles. Their problem with battery life and weight is only being solved currently. Other reliability spoilers such as rheostat and potentiometer controls were also a part of the design. They were not noticed because of the major unreliability of gasoline powered cars at the time. Now that electric vehicles have caught the public fancy, one of my current engineering tasks is replacing wear-prone potentiometers with hall effect sensors. The buying public has come to expect components that last the life of the vehicle. Again a reliable sensor by itself is not enough. Computer intelligence is married with the hall effect sensors to insure safe and predictable vehicle operation

A Dual Hall Effect Pedal replaces wear prone switches and potentiometers with
magnetically coupled precise control

Test Drive

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Car on test track

Car on test track

As a mechanical engineer my focus is usually on mechanical devices. It is necessary
to remind myself that a test drive is usually needed to discover how the rest of the population reacts to those same devices. Surprise! Surprise! most people are not naturally mechanically inclined. This becomes obvious when the general public participates in test drives. The software industry discovered the same truth. Beta testing with real users is the way they arrange test drives. High powered artificial intelligence built into programs is of little use if you cannot get the friggin! computer to turn on.

The simple Human Machine Interface action of pressing a button becomes a nightmare if there are too many of them

The simple Human Machine Interface action of pressing a button becomes a nightmare if there are too many of them

As Moore’s law increases the number of transistors within the computers that we use, the engineers, business owners and, investors who invent the devices and programs that use this horsepower are very tempted to overwhelm the buying users with a multitude of blinking and flashing lights to herald the latest and greatest. I admit that when I was inventing the Chrysler Mini Van, it was very frustrating that the general public did not recognize how great it was while I was designing it. That public recognition became even more important when we first tried to sell some. I understand why the designer of my electric kettle wants to highlight his addition of a digital temperature display into the device. Rubbing it in my face by incorporating a seemingly random sequence of four button pushes to turn the device on, spoiled my perception of the benefit.

The Mustang became a sports car for the masses

The Mustang became a sports car for the masses

The throttle pedal is one of the key interfaces between the driver and the vehicle. The Mustang succeeded because of an invisible triumph in this area by the Mustang design engineers. Their throttle linkage made the Ford Comet compact car chassis feel like a sports car. As I launch a new generation electric vehicles, similar attention is being applied to the throttle. The latest generation dual hall effect encoders are being used to create a tight linkage between the vehicle and the operator commands. Embedded computer intelligence is being programmed to achieve the “feel” of expensive mechanical links. User invisibility is still the key. We still need to wait until the vehicle users test drive our improvements before we can expect recognition. I have seen this before with the Minivan

Au Courant

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A multiple exposure picture (one of 68 Colorado Springs images created by Century Magazine photographer Dickenson Alley) of Tesla

A multiple exposure picture (one of 68 Colorado Springs images created by Century Magazine photographer Dickenson Alley) of Tesla


au courant
Per Merriam Webster
adjective au cou·rant \ˌō-ku̇-ˈräⁿ\
Simple Definition of au courant
Popularity: Bottom 50% of words
: knowing about the newest information, trends, etc.
: stylish or current.

The 19th century started with the battle of the currents. Thomas Edison battled with George Westinghouse and Nikola Tesla. The DC current generating system invented by Edison was less suitable for transmitting current over large distances. Westinghouse put in place a 3 phase AC system invented by Tesla at a generating plant beneath Niagara Falls to supply power to the businesses of Buffalo. The big advantage of AC was the ability to use a simple transformer to change the voltage. High voltage transmission lines make long distance transport of electric power affordable. The original 25 cycle AC morphed into the 60 cycle AC power grid that spans the country. DC power faded into battery powered applications like car starter motors and flashlights.

Even though the transistor was invented in 1947, it remained a low power DC device into the 80’s. Chrysler invented an electronic spark advance and introduced it in 1978. It was taken out of service in 1980 because the ballast resistor needed to protect the power transistor proved to have a poor service life.

Balast resistors protected the power transistor running the spark coil until 1982 picture by Mr Choppers

Balast resistors protected the power transistor running the spark coil until 1982 picture by Mr Choppers

Finally in 1982 we had a transistor that could successfully process a higher amperage 12V DC application. We no longer think about changing points and plugs. This used to be a biannual ritual.

Even for the engineers leading the charge into the bright new future, technology advances catch us by surprise. Moores law on the ever increasing number of transistors on a chip is well known. Other related advances in silicon power transistors seem to happen invisibly. We all got used to 12 volt DC vehicle power systems. Now with have hybrids and electric vehicles with DC voltages north of 800 volts. Driving this charge is the serious drop in the price of power transistors. I was reading about a tiny DC to DC voltage converter that can squeeze a whole bunch of extra life out of a simple dry cell battery.

DC to Dc voltage converters have dramatically dropped in price

DC to Dc voltage converters have dramatically dropped in price


The harder part is switching gears myself and utilizing inexpensive 48 volt DC to 24 volt DC converters when designing my current new electric vehicle offering. They are a surprisingly good match to low current LED lighting.

DC current will splash back onto the public stage. We are seeing it already in very long distance transmission lines, electric vehicles, superconductive materials. The development effort needed to bring this to pass has been going on for a while. To the observing public the change will appear to happen overnight.