All posts by admin

Pi Day Quiz 2017

1) Building a wooden window frame, is it stronger to use a circular or an L-shaped bracket over the corner joint?

2) What is the minimum number of nails or screws needed to attach the bracket from Question #1 so that the frame is limited in how it can distort along two axes (X and Y axis)?

3) Does a spherical ice cube last less time, more time, or the same amount of time as a cubic ice cube?

4) Does a cubic ice cube cool the liquid it is submerged in faster, slower, or the same speed as a spherical ice cube?

5) An electrical circuit can be built to reduce frequencies higher than a ‘cutoff frequency’.  What is a formula showing the relationship between the capacitance of the circuit and the ‘cutoff frequency’?

6) An electrical cable is coiled for shipment and when installed still has a 2.5 cm diameter spiral to it.  How does that change the total length of the cable?

Electric City Bike Rescue in September

Last month our resident photog captured moments at the Electric City Bike Rescue. This operation services the public every Thursday at the Edison Tech Center. See our Contact Us page for updated hours.

Every year many tonnes of steel are wasted as it is thrown into landfills across the country. Much of the population has no knowledge of how to fix even minor problems on their bikes, so when they encounter a problem they just throw it away and buy a new one. Not only is this a waste of our planet’s resources, but it is also a shame considering many less fortunate people in our community could use the older bike. The Electric City Bike Rescue helps people understand mechanical basics through applied effort on their bikes.  Here are some photos.

800-IMG_2566 800-IMG_2527800-IMG_2532800-IMG_2548800-IMG_2554800-IMG_2570


Volunteer Opportunities at the Edison Tech Center in Fall-Winter 2016

This fall the Edison Tech Center closed its displays in order to change them out. After a number of years we felt it was a good time to freshen up our public area. The Electric City Bike Rescue program continues each Thursday all throughout the winter.


Behind the scenes help – We are looking for people with a strong interest in technology and engineering who would like to help build the new displays and use their technical or trades background in this effort.

Bicycle Rescue Volunteers – If you would like to help on Thursdays please contact us and let us know you’d like to help with this program.

Submission of engineering papers and curriculum – If you’d like to publish your papers on our website or blog please contact us. We are looking for non-political, non-religious engineering papers which can look at history or current technological events. Many of our online resources have been enriched by experts in the area who added sections to our pages.

Contact Us

Computer Hard Disk Drives

This week Seagate Technology re-released one of our videos to its subscriber base on YouTube. In 2014 as part of the Iron in our Electrical World series we covered magnetic hard disk drives as one of the many ways in which iron is used in electrical engineering.

Engineer Joanne Larson did an excellent job of walking the viewer through the parts and basics of how a HDD works. Here are some photos and some basics covered.

Read and write heads
Head stack assembly

While you may visualize a hard disk as  silver-colored disk spinning with an arm reading it similar to a record player, it actually is an array of disks with many read and write heads on BOTH sides of the disk. This is done to maximize the read and write speed and the quantity of data which can be stored on the disk. Above you’ll see the arm separated from the assembly. The read and write heads are positioned near the tip of the arms. The idea of the array of disks goes back to the first HDD made in 1956.

Why is it called a “hard disk”?

Floppy disks of different sizes on display at the Edison Tech Center

Today we use HDDs and solid state storage for computers. The disks are rigid and a fixture in a computer. But at one time we had “floppy” disk drives (FDD). Both floppy and hard disks coexisted occupying different uses for many years. The idea of the floppy disk came from magnetic video/audio tape and the hard disk drive. As you will see from our webpage on Magnetic Recording audio/video data is recorded in a medium filled with tiny soft iron pieces, the iron bits would align themselves according to how the write head (a magnet) aligned them. You will see the head also called a “transducer”. This alignment of magnetic “directions” can be read later on and converted into an analogue signal. IBM developed the 8″ floppy disk called the Memory Disk (80KB storage) in 1971.

Early engineers at IBM figured out how to use “reel to reel” magnetic tape (1951) to store binary data which had sections useful for given tasks that could be read later on by rushing through the tape to read from particular sections of the metallic tape. The problem with this is having to rewind/fast forward through tape. Transfer rates for the early tape started at 7200 characters per second. In comparison the common compact cassette tape used for music by the consumer had a transfer rate of 2000 bits per second.

A flat “disk” of the similar magnetic data could be read faster by allowing sections to be read by their address or position on the disk. IBM developed the hard disk in 1956. The disk was an array of 50 24″ disks which could hold 5 million digits of storage.

HDD density
As of 2014 300,000 tracks could be laid out on one inch of one side of the disk

The need for higher density of data storage lead to advancement in magnetic storage technology. The hard disk evolved as an aluminum disk (aluminum is light-weight and allows for high-speed rotation without warping) with a magnetic coating on the outside. Many alloys have been explored to attempt to create the highest density possible while keeping the storage stable over a relatively long time. The job of engineers is very tough in HDD design as work must be done on a microscopic level and one must work with many fields of engineering.


The write pole seen magnified 85,000 times. Some parts here are only a few molecules thick.

Materials engineers, chemical engineers, mechanical engineers, electrical engineers all must work together to create a product that is better than any other before it. Each year the frontier of what can be done is advanced. All this work occurs on its own plane separate from the common media buzz. While marketing for Apple and other companies love to simplify advancements and declare that “optical data storage is dead” or that magnetic storage is the past, this is simply noise and not engineering. Throughout history engineers have surprised everyone by taking older technologies and breaking through a barrier that had stopped people in the past, this can result in a leap beyond the current popular method. Sony, Seagate and others are continuing to make advancements in storage density that help create new uses for magnetic storage.

Now see the video below where Mrs. Larson explains the hard drive:


IronPromoMiniThe Iron in our Electrical World Program is a collaboration of the Minerals Education Coalition and the Edison Tech Center. In the program we highlight the importance of materials engineering, the role of iron in our society and how this material is used in technology design all around us.


Videos About Steinmetz

Over the years the Edison Tech Center has made many videos which mentioned Charles P. Steinmetz. Many of you have only recently heard about this dwarf pioneer who revolutionized our world with his work on AC power. Not only Steinmetz’s direct work advanced technology, but his mathematics work which is still used today. Here are a list of the online videos we have published on Charles P. Steinmetz:

Steinmetz’s life before he joined General Electric and his career launch:


Steinmetz is hired in the US for the first time and founds the General Electric Research Lab with E.W. Rice Jr.:


Steinmetz’s pastimes: his 1914 Detroit Electric Car and his Canoe at the Edison Tech Center.


General video of photos and film of pioneers including Steinmetz:


The Metal Halide Lamp, found in almost every town and city in the world, developed by C.P. Steinmetz in 1912:

Old film Steinmetz: the Man Who Made Lightning (From the Schenectady Museum Archives)

Thanks for watching! Subscribe to our YouTube channel to keep in touch with our stream of videos.

Events at the Edison Tech Center

The Edison Tech Center in Schenectady has been host to many events over the years. This fall we look forward to a variety of events currently in planning. We will continue the film showings and Electric City Bike Rescue meetings as well as a few new things.

Looking back at last year we had a few events related to the International Year of Light. In December electrical engineer John D. Harnden Jr. made a presentation showing the latest and greatest of consumer light technology. Lighting collector and expert Rick DeLair conducted a video tour of his collection of lights including early Edison-era incandescents to huge rare street lights.

Last year was the 150th Steinmetz Day in April. Craig Cantello made a presentation on lighting technology for the event. Pioneer of microwave technology Rudy Dehn hosted an event in June for kids with a Van de Graaf generator and other cool teaching toys. Dr. Ron Fearing kicked off the spring with an event on robots engineered after insects. Dr. Fearing has a specialty in crawling and flying milli-robots.

The Edison Tech Center is often host to private group events such as Dr. Frank Wick’s engineering student’s events and local old age homes. If you’d like to bring a group to the Edison Tech Center please contact us and ask about our facilities. If you are interested in attending events the easiest way is to like us on Facebook where we post events. You can also check our Google Calendar on our page.

Our Facilities

The “Wizards of Schenectady”, Telling the Untold Stories of Great Engineers

It was 9 years ago when the Edison Tech Center launched the Wizards of Schenectady Series. The series was the brainchild of renown local television personality Ernie Tetrault and others at the Edison. The idea was to launch a full-scale biographic documentary on each of the amazing inventors and leaders at General Electric. There were so many incredible untold stories that it made total sense to package this history into a format that everyone is familiar with. The name “Wizards” came from the historic description of Charles Proteus Steinmetz which was described as the “Wizard of Schenectady” by national newspapers.

As the producer of the series one of the things I find most fascinating about the biographies was how each one touched on key events in US history. From the formation of RCA to the Cold War each person we covered played a role. The series is great in that it shows how great technical advances in US history were made thanks to people, people with families, hobbies and real lives that you can connect with. While the national media loves to grasp onto larger-than-life personas like Thomas Edison and Nikola Tesla, the reality was that innovations mostly happened from those where not flamboyant and self-promoting. The Wizards of Schenectady Series is about ordinary people in special circumstances, and thanks to educational institutions and companies with strong infrastructure they were empowered to create, and given all the tools and people they needed to make it happen.


Guy Suits at the lab

The first in the series we worked on in 2007 was C. Guy Suits and his Flying Machine. The story is more about his engineering and leadership skills than a ‘flying machine’, but his float plane hobby is certainly covered in the show. Ernie Tetrault and Jack Aernecke lent their skills in television production while local people who worked with Suits told the story. Suits ran the GE Research Lab during the exciting post war period as innovations of the modern world changed our lives. Suits, like many engineers had a knack for not just physics, but physical crafts like wood working, oriental rug repair, boomerang construction and the outdoors. Suits was respected by the legendary engineers working under him as a leader. His leadership and management experience during a transition period helped found the GE Global Research Center as we know it today.
The Wizards of Schenectady: C. Guy Suits and his Flying Machine was shown at the Electric City Film Fest where it won first place in the documentary category.

Carl RosnerThe second piece in our series highlighted another engineer from a very different time in history. Carl H. Rosner’s story is one that includes two parts, the first being his survival of the Holocaust, and the second part being of his work at General Electric and founding Intermagnetics General Corporation. Rosner’s story is one which is inspiring for engineers as it shows how persistence and innovation lead to life-saving technology. Rosner and his various teams over the years specialized in superconducting technology which is a really fascinating area! The Edison Tech Center’s production Wizards of Schenectady: Carl H. Rosner Pioneer in Superconductors has been shown many times to future generations of children thanks to the talks organized by Mr. Rosner himself and the Holocaust Survivors and Friends Education Center.
This documentary has been shown at the Electric City Film Festival and the Ballston Spa Film Festival. Parts of this documentary have been published and viewed by hundreds of thousands.

Harold ChestnutThe story of Harold Chestnut is one that touches on everything from early mechanical computers to broad political policy. We find the subject of systems engineering to be amazing as this area which “Hal” Chestnut contributed to is applicable in everything in our lives. As a control and systems engineer Mr Chestnut advanced many technologies from jet engines to the NASA moon efforts in the 60s. He was not just a great engineer but a natural leader. Chestnut helped with organization of the IEEE, IFAC and other groups. For this video we interviewed the world’s leading control engineers for their commentary on the life and times of Mr. Chestnut. From Seoul to Moscow to Schenectady we investigated the impact Hal Chestnut had on engineering. The Wizards of Schenectady: Harold Chestnut Pioneer in Automation has been shown to engineers around the globe and a rare biography for someone working his field.

Rice LegacyWizards of Schenectady: The Rice Legacy covers three major figures in recent technological history. The documentary starts off with E.W. Rice Jr. who was not only a contributor to early electric power history, but an important leader in General Electric at a critical time. E.W. Rice’s life is interlinked with many important people his age including Elihu Thomson, Thomas Edison and C.P. Steinmetz. What’s great about this episode is that you learn a lot about the early history of electricity. Expert Wise helps tell the story of Rice and the times.  Chester W. Rice was an innovator who worked at the GE Research Lab along side other legends like Langmuir and Steinmetz. C.W. Rice is known for contributions in the areas of acoustics and mechanical engineering. Martin Rice was a figure on the publicity side of the industry, working for GE’s broadcast arm of the business. The Rice documentary took a few years to research and produce and paints a unique picture of the fascinating era of the early 20th century.

Nancy Fitzroy

One engineer and innovator who stuck out above the rest is Nancy D. Fitzroy. We decided to cover her life in the Wizard’s series in 2009 after an interview conducted by Ernie Tetrault. Nancy is a mechanical engineer specializing in heat transfer. Her specialty was fun because it was applied to many diverse types of projects including the heat tiles on the space shuttle and the first nuclear submarines. Nancy was the first woman president of the American Society of Mechanical Engineers and has been a role model to other women. This documentary features commentary from well-known engineers and physicists.

One great documentary which is not part of the Wizard’s series but predated the series is Langmuir’s World. This show does a great job of condensing the life of legendary engineer and physicist Irving Langmuir. Irving Langmuir was a driving force in the GE Research Lab and an important part of the world’s physics community. This story covers the many contributions of Langmuir including the invention of a much more efficient light bulb, and it covers his personal life and hobbies.

Excerpts from the Wizards of Schenectady Series have been published online and reached over a million viewers. The full episodes are available from the Edison Tech Center on DVD. Contact us and make a tax deductible payment of $30 to our Paypal account and we will send you an episode of your choosing. Proceeds go to support historical preservation of artifacts and production of educational media which reaches many young people each day.

Carl Rosner Documentary now in HD

Eight years ago the Edison Tech Center premiered the award-winning documentary on engineer Carl H. Rosner at the Electric City Film Fest. Recently we have re-released the documentary in widescreen SD format for DVD and HD format online.

Ros-BuchBuild400pxlThis touching documentary features the life of entrepreneur and superconductor expert Carl Rosner as he survives wartime Germany, Buchenwald concentration camp and goes on to found a successful and innovative company which finds its niche in MRIs. This biography is part of the Wizards of Schenectady series and has renowned voice over artist Jack Aernecke take us through the story.

The newly released promo for the documentary below summarizes some of the story covered in this biography:

Carl Rosner documentary
The documentary features interviews with other great engineers like Pier Abetti, Howard Hart, Gary Morrow and more.

Mr. Rosner has been working with the Holocaust Friends and Survivors Education Center in Albany  to share his story again and again to  children and adults. This work is vital to preserving the memory and lessons learned from  the Holocaust and World War II. In addition to the story of  loss and deprivation is the story of hope and building a new life. Mr. Rosner has worked with some of the best engineers in superconducting technology history to create life-saving machines. The story of Intermagnetics General spinning off from General Electric is a great story as it was rare for a spin-off to survive and grow to become a power in industry.

If you live in the Albany-Schenectady region, we invite you to check out the Holocaust Survivors & Friends Education Center for film showings and other events. As the producer of the documentary and  a young person, I was moved by the experience of reviewing original films and testimony from the Holocaust. I believe that every young person from every ethnic background should learn about this history. Mr. Rosner’s documentary along with other films and presentations can help widen our horizon of understanding about  how hatred  can lead to genocide and the bravery of those who resisted and saved others.

Contact the Edison Tech Center to order DVDs of the documentary and full interviews between Ernie Tetrault and Mr. Rosner

Holocaust Survivors & Friends Education Center: 518-694-9984

Electrical Technology and Mining Gear

After our recent article on the lighting blog about lighting technology for caving I thought I’d check out the Argo Mill museum to see what artifacts they have. Despite the hostile environment of mines the “new” technology of electricity quickly lent itself to the industry of mining in the 1890s.

Oil-wick cap lamp and helmet on display

Oil and kerosene lamps were used by miners prior to the 1890s. These lamps produced heavy fumes and were a problem when tipped. Despite these problems early miners had to deal with this and were always looking for a better light source.

In 1891 Westinghouse built the Ames Power Plant near Telluride to light and power the Gold King Mine. While there were many problems to solve, the effort was generally a success and set an example of how electricity could revolutionize underground operations. Around the same time Thomas Willson sold his patent of the carbide lamp to Union Carbide and the carbide lamp took the world by storm as they were good for everything from bicycles to lighthouses to mining operations. These acetylene gas lamps were great in how they could be tipped at angles as people negotiated narrow passages and they’d still work great.

Different types of carbide lamps, these could be mounted on a helmet or there are hand held version with handles.
Dynamite detonation gear

The Argo Mill has some great artifacts on display of not only lighting technology but early telephone communications gear and dynamite detonation gear. Another way in which electricity revolutionized mining was the development of small powerful electric locomotives to haul carts of ore. These systems replaced the inhumane system of having donkeys drag the tons of rock out. Elihu Thompson and other pioneers of the time worked on cutting edge powerful electric motors to drive these devices. You can see an example of one of these small electric locomotives at the Argo Mill among other interesting artifacts of the 1800s.

Electric Mule and ore carts. These had a pole that connected to power lines located on the tunnel ceiling.
An electric mule motor designed by Elihu Thomson. These were DC motors powered by overhead wires (catenaries). The floor of the mines were often wet so the ceiling was the safest place to put the wires.
Electrical boxes located in the Argo Mill. Powerful electric motors turned belts that rotated machinery used to refine ore to extract the gold, silver, zinc, copper and other metals.
Control for the speed of the electric mule
An early electric headlamp for miners with battery pack.










Glass and ceramic insulators used for telegraph, telephone and utility power in the mines.
Large insulators for supplying AC power to the mill
Steam powered drill used for boring holes into rock, later dynamite would be inserted.
A telegraph key from the 1800s
Early telephones which connected the mine workers miles underground to the surface.
The classic Wheat Lamp used by miners after the 1980s
A durable double bulb incandescent handheld lamp used by miners

We recommend visiting the Argo Gold Mill as there are all kinds of engineering relics of the steam and electrical age. Their website is found at

Also see our article on caving lamp technology history which is related to mining lamp history on our lighting technology blog.