Category Archives: Basic Analog Circuits

Eric Rosenthal Basic Analog Circuits

Magnetic Stimulation of Neural Tissue

When testing out designs for Mykro Dot LED earrings in the late 70s, I discovered that using a an earring wire to carry 1.7 Volts (20 ma) for a couple of hours a day was enough to cause the tissue around the earring piercing to thicken in three to five days. Not wanting to further expose myself to legal action, I opted for a less elegant solution for earrings.

A classmate asked me about stimulating the brain by using electromagnetic pulses as a possible thesis project.  I am all for pushing the limits of cybernetic technologiesX. The block diagram below is representative of interesting research.  Unless you are a budding sociopath testing EMF/EMP technology in its current state of development on yourself, people you know, or strangers, resonates as an extremely bad idea.

Click for a very interesting website on Bioelectromagnetism


Addendum: I just came across this site when researching Helmholtz coils that was all about magnetic healing (Mesmer, anyone?).   There may be something to this in the medical profession for treating Alzheimer’s.  But it still seems like a Radium cure to me.


put non-rechargeable batteries in a charger.  I know, I know: I should have known better.  But after a lifetime of playing it safe, I put a D cell in my charger.  About a half hour later it made a sound like a high-speed fan throwing a bearing and leaked steaming electrolyte all over my charger and sprayed material onto a wall three feet away!  I was fortunate that the spray just happened to hit the wall.  Had the spray hit me in the eyes I have little doubt that I would have been blinded.

I threw the battery out while it was still spewing its leaking innards.  Not much there to see except ooze.

Faraday’s spiral

Earlier this semester I presented a model based on an Alexander Calder mobile.  It was fun to build and, oddly, I learned a lot.   During presentation Artist-Professor Eric Hagan made a remark which resonated to what another professor said to me during my first semester at ITP.   While I forget exactly what he said, both comments expressed the same thought:  “OK that’s great.  But I’d like to see you go further.”   My immediate reaction was, “further than Calder?  Not possible.”  But it was still a challenge that preoccupied my semester.

Time in graduate school has given me the space to examine much of what has been an endless source of fascination for me since I was six years old, which is pretty much everything!

Specifically though, just now, the preoccupation is with nuclear forces; the movement of sub-atomic parts/units/fields/packets/waves/quanta of energy (electrons, protons, neutrons, etc.) which I am trying to wrap my consciousness into.  This is a world whose architecture would seem to be modeled after a celestial map of creation.  Every detail seen, appreciated, and missed,  possesses significance.  I cannot begin to imagine a world as complex as human society on an atomic, cosmic, human-sized scale: that’s more than my pea brain can comprehend.  For now I am trying to understand one tiny phenomenon at a time.

This past year I have been thinking more about magnetic fields and how it is that non-magnetic objects are physically moved through space using otherwise invisible energetic agents.

Wandering the streets of London about ten years ago, I discovered a museum which featured Michael Faraday’s laboratory in the basement of a London townhouse.   Seeing his old wooden work bench, the tools which he used, a letter to him from Galvani, and a model of the first toroidal transformer, was an extra-ordinary experience.  I couldn’t help but think that his work area looked a lot like mine, except that he had more things made with wood, brass, and style.

Faraday discovered a lot things.  Electrolysis and electroplating for one (two?).  Another find (besides the dynamo generator) was the movement of electrons through copper wire.

That’s the background, how I arrived at creating sculptural objects from something simple while learning and discovering so much in the process: thank you  Erics Rosenthal and Hagan for leading this horse to water.

…. the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible ….” – Albert Einstein

Watching the wire repeat an eccentric orbit without gears, flywheels, pulleys, or sails is fascinating.  Magnet + Electrochemical Cell (source of electrons) + Conductive metal (non-magnetic wire) + correct arrangement = Motion.

When I worked on repeating Faraday’s experiment, I learned more than I ever did through reading about him and his work.  Experimenting with varying strengths of magnets and cells as well as the diameter of the wire, and how these variables  with affect the speed and strength of movement is very interesting.

The demonstration on this page would have been cause for burning at the stake in 1693
The demonstrations on this page would have been cause to be burned at the stake in 1693

Putting these experiments in an historical context is interesting for other reasons.

The Wonders of the Invisible World:
The misguided at Salem’s Witch Trials missed the mark.  Real magic occurs at the subatomic level.   It is a realm where forces which would otherwise remain invisible are made manifest through intensive research, theory, and experimentation.

Every technology which we interact with has beginnings which are no less inspiring now than when they were first discovered.

Without these discoveries, Duracell batteries (cells), copper wire, and magnets would not be the common objects which they are today, as well as the foundations of still developing machines which are fundamental to the world which we inhabit.


Printed Circuit Boards: 1903 – 2013

A quick on-line search and I found out that the ubiquitous circuit board had its start in 1903 thanks to German inventor, Albert Hanson.

It looks as though a hundred and ten years later the technology might be catching up with our desktops:
Screen Shot 2013-11-17 at 9.55.28 AM

The process uses an inkjet printer whose hacked cartridges lay out an ink of conductive silver (for the time being).  As a side note, a recent field trip to NYU’s Advanced Media Services revealed that one of the rapid prototyping machines uses HP inkjet cartridges to print rock-hard objects using what may have been gypsum as the binder.

In the same way that the hand-drafting of printable wiring diagrams was replaced by CAD, this printable technology would be welcomed by anyone who has ever had to figure out how to best dispose of the toxic sludge which always results from the chemical milling of copper-clad circuit boards.

Like using whale oil for lighting, some technologies should be retired.

There is a kickstarter for a promising project… heck, I want one too.Screen Shot 2013-11-17 at 1.26.36 PM

Peter Terezakis
ITP Master’s Candidate
Tisch School of the Arts

Expensive – because they are worth the money.

The entire family of Pomona banana jacks and plugs are engineered works of beauty – and function.  They are reliable, robust, and were designed by engineers for engineers.  If you know what you are looking for, you can find them for less money than what they are currently selling for on eBay.  Click here for the Pomona Electronics data sheet.

Screen Shot 2013-10-05 at 10.21.00 AM Screen Shot 2013-10-05 at 10.21.09 AM Screen Shot 2013-10-05 at 10.21.27 AM Screen Shot 2013-10-05 at 10.21.54 AM

Universal Unlimited Command & Control Console

Universal Unlimited Command & Control Interface, part 1.

Dreams are meant to be channeled here.  Creative thought engendered through haptic, auditory, and visual feedback of a polyutilitarian assemblage of electronic and mechanical components.

Here is version 1 after laser cutting and bonding of acrylic:


A friend remarked that it was difficult to see.  I tried to explain the transparency of function aesthetic and was met with a blank look.  The image below should make the interface easier to see.


If you still have difficulty, here it is on its own.  Unfortunately, I have run out of nuts to fasten the binding posts and banana plugs in place.  This is a giant bummer.  I have containers of them at my studio in San Diego.  Looks like time to break out the hot glue.

I’ll start soldering tomorrow after I install the rest of the contacts.





Timeline for photovoltaic technology

1839 – Nineteen-year-old Edmund Becquerel, a French experimental physicist, discovered the photovoltaic effect with two electrodes in an electrochemical cell.

Becquerel’s 1839 PV cell

1887 The photoelectric effect was first observed by Heinrich Hertz.

In 1905 Einstein created the mathematical and theoretical framework to explain the photoelectric effect.

1915, after ten years of experimentation, Millikan proved Einstein’s photoelectric theory correct.

In 1921 Einstein received a Nobel Prize, “for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.

1954 Bell Labs (New Jersey) developed the direct ancestor the silicon solar cell.
Solar Cell Patent from 1957

1955 – Western Electric licensed commercial solar cell technologies.  Hoffman Electronics-Semiconductor Division created a 2% efficient commercial solar cell for $25/cell or $1,785/Watt.

“12 Volts from one reflector? Do you know what this could mean?”

“It means that if we knew enough about that electrical field, we could operate every appliance in Oak Ridge by sunlight.”

“[Do] you mean it converts light into electric current just like that?”

“Just like that.” – Cosmic Man, 1959

2013 – Fossil fuel businesses introduce legislation in nineteen states to curb the use of photovoltaic/renewable technology.

It has taken over one hundred and seventy-five years for the observations of a nineteen year-old electrochemical experimenter-scientist-tinkerer to develop into a technology which has begun to threaten the hegemony of petroleum-based public utilities.

We can only wonder about other discoveries which languish at the periphery of physics waiting to be developed for the betterment of humankind.   I’m not quite certain why the discussion of Low Energy Nuclear Reactions (LENR) causes a problem in so many areas: many common day events of our physical world exist due to sub-atomic actions occurring at room temperatures.

Since the photoelectric effect took nearly 200 years to become a useful technology, it doesn’t seem far-fetched that something positive will come from the observed, poorly understood phenomena  known as Cold Fusion.  If the investor in the Fortune article below is correct, we may see something truly marvelous in a very near future:

They missed that heat was the main by-product. In addition, I learned that there have been nearly 50 reported positive test results, including experiments at Oak Ridge, Los Alamos, EPRI, and SRI. Q: The conventional wisdom is that LENR violates the laws of physics. A: That’s right. To create fusion energy you have to break the bonds in atoms and that takes a tremendous amount of force. That’s why the big government fusion projects have to use massive lasers or extreme heat—millions degrees centigrade—to break the bonds. Breaking those bonds at much lower temperatures is inconsistent with the laws of physics, as they’re now known. Q: What changed your mind? A: Scientists get locked into paradigms until the paradigm shifts. Then everyone happily shifts to the new truth and no one apologizes for being so stupid before. Low temperature fusion could be consistent with existing theories, we just don’t know how. It’s like when physicists say that according to the laws of aerodynamics bumblebees can’t fly but they do.