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A Tribute to Benno

By Frank Greenhalgh

One of the advantages of working in engineering is that you get to meet a number of very interesting people. Engineers tend to be achievers and generally have fairly high opinions of their ability. Sometimes they're right and sometimes they're wrong. In any case they are always interesting.

In the early 60's I was working for a small company on Long Island. The company was in the process of drastically remaking itself. The main product line had been custom militarized analog meters, which were being displaced by digital displays. The company's marketing consultant recommended that a new product line (custom military power supplies) was required. I was hired because I had worked designing power supplies in my last two jobs. That was by accident but it seems that destiny had Power Supplies written all over my nametag. Pretty soon, it became obvious that we were not going to crack the existing market. Ultimately, we found ourselves quoting jobs that all the other companies had "no bid." Generally, this was due to size and weight restraints. When the customer asked how we were able to meet the small size, we answered: "Switching regulators." I had seen an article describing the concept of switching regulators and built a breadboard to prove that it worked. It was this breadboard that gave us the courage to bid (and get) these jobs.

During the design phase it became obvious that one of our weaknesses was that we didn't know how to design transformers! We would write a specification showing the input and output requirements and send it to a transformer company. The turn around time could take weeks and even then it might not work correctly because of peak currents or leakage inductance. Sometimes it was larger than we thought it would be. Ed F. our VP of Engineering was pulling his hair out as each job was delayed due to transformer and inductor problems. Then he acted.

One Friday morning Ed called us into the conference room and introduced us to Benno. "Benno" he said, "is an expert in the transformer field. He has been retained to teach us the art of transformer design and manufacture. In the future, Benno will come and work with us every Friday. He will spend Friday mornings in engineering teaching us how to design transformers, and he will spend Friday afternoons setting up winding machinery and potting equipment in manufacturing, and training people to wind and pot and terminate magnetics." We were going to be capable of designing and manufacturing our own transformers!

Transformer Design:

Each Friday morning Benno would appear in engineering. He would drive to work from his apartment in NYC (about 40 miles) on his BMW motorcycle. He refused to wear a helmet claiming a personal right to be reckless, but he did wear a tweed jacket, white shirt and tie. Benno impressed us. He knew the transformer business from one end to the other. He had been the Chief Engineer for a small transformer company in New Jersey and had to do it all, from sales to design to manufacture.

Benno was able to see transformers as no other person I ever met could. He taught us to understand these previously mystical pieces of iron and copper for what they were.

Some of the basic concepts he taught us were so simple yet not obvious to us.

NpIp = NsIs, Ampere Turns in Primary = Ampere Turns in Secondary

The ampere turns in the primary MUST equal the ampere turns in the secondary (Benno would neglect core losses to simplify concepts)

Wire size is to be determined by first selecting the cm/amp (circular mils per ampere) based upon core size and temperature rise.

Calculate wire size using the RMS amperes based upon waveform.

The wire size used should be selected to yield a homogenous temperature rise across the entire cross section of the winding area, yielding the most efficient design. This simple concept was so important to efficient design.

Benno gave us formulas that he had developed. They made it easy to calculate the turns required based upon frequency and core types. He gave us wire tables that he had personally developed. Ordinary wire tables give you the parameters of wire in dimensions such as "Ohms per Thousand Feet" and diameters for bare copper. Benno's tables gave us a listing of "Milli-ohms per inch." The diameters were given for single and heavy (formvar) coating. Also, each wire size included the "turns per Inch" and size of interlayer (nomex) insulation that should be used.

He also gave us a winding instruction form to be filled out for the transformer we designed. This form told manufacturing exactly how to build the transformer. It calculated the percentage build to check the design. Entries for each winding's resistance and power dissipated were included (but optional). These tables and formulas could not be found in any books, Benno had developed them himself. In 1963, the only instrument you had was a slide rule. Benno calculated each table by hand to use as his private tool to allow efficient transformer design. Now he was sharing it with us.

In no time, the mystery of transformer design melted before us. We became masters of our own domain. Our new hero Benno taught us the Zen like discipline required, to produce a perfect design the first time. Soon we were making up our own tables, tables telling us what the winding length and height was for various bobbins. We were transformer designers.

Benno also taught Dave and Wes in production how to build these devices. They enjoyed learning how to prepare the insulation, to draw a perfect vacuum and to terminate the many taps we were asking for. Soon we had a well-organized transformer manufacturing capability.

Friday Evenings

When Benno was through with manufacturing, he would come visit engineering on Friday afternoons. Benno wanted to learn switching power supply design. As great as he was with transformers, he knew very little about transistors and so he became our student on Friday afternoons. At five o'clock, we would retire to the local pub for happy hour. Benno would join us. There we would drink Heinekens Beer ($0.50 a bottle) in large quantities and discuss designing power supplies and transformers. On many a Friday evening, I would invite Benno to join me for dinner at my home. Thankfully, I had (and still do), a wife that didn't mind my surprising her with dinner guests. During these dinners and continuing conversation after, I learnt a great deal about the rest of Benno's life.

Indonesia to Paris

I was about twenty-six at the time and Benno five years older (31). My entire view of the world was New York. Born in Brooklyn and raised in Queens (Boroughs of New York City) I had never been further west than Ohio and no further east than Greenport, Long Island. Benno told a story of a far different life. He was born the son of wealthy and royal Dutch landowners in Indonesia. Benno soon had his life change when he was separated from his family and placed in a prisoner of war camp as a young boy. He told of how he earned the respect of his Japanese guards by repairing anything electrical that was broken. Benno also developed a love for hot, spicy food during that period. After the war, he returned to Holland and finished his schooling. His family evidently lost their wealth in the war. Benno attended college as an engineering student in Holland and then earned an MA at the Sorbonne, travelling by motorcycle and working to support himself. When he left college, he worked in Europe for a while and then came to the US. In the US, Benno ended up running a small transformer company in New Jersey. He left the company and rented a small basement space in his apartment building. There he set up ETCA (Electronic Transformer Company of America), his new consulting business. Soon, he was travelling all over New York on his motorcycle calling on customers designing their magnetics and trying to design power supplies. Benno was also a very competent tennis player and fencer. He belonged to the NY Athletic Club and was known to invite people to come and play tennis with him on center court, where he would beat them handily. In addition to his other talents Benno also could speak about six or more languages (English, Dutch, French, German, Italian and Japanese).

New York to Italy

One Friday, Benno announced that he was leaving. He was going to Italy to run a transformer company that one of his clients had bought. When we asked him why he would leave the US to live in Italy, Benno replied "Engineers in Europe are treated with great respect. In the US they are not. I will be given a much better opportunity in Italy than I have here." Just the way he came he left about one year after he appeared.

Italy

In 1981, I went to Rome on business. I had designed a power supply for an Italian company (ELMER) and went to witness testing of it in their system. The first morning I was there I was talking to the customer when I felt a slap on my back. I turned to see Benno smiling at me. What a coincidence to see him there! Benno and I renewed our friendship as if there was no twenty-year space. Benno told me he was "running a half bankrupt power supply company." It seems that politics had forced him out of the transformer company he had gone to Italy to work for. So he borrowed some money and started his own company, designing and building transformers and power supplies for the military and OEMs in Italy. I visited his company, which had about ten employees. Benno did everything. He did both the electrical design and the mechanical design. He also was the sales and purchasing department. When he had a spare moment, he would design his test equipment. What a difference from the efficient transformer designer he was when I first met him. Benno had fallen prey to the Achilles' heel of engineers. He tried to do it all. His company was totally limited to his output. Financially, he couldn't hire another engineer so he had to work, long inefficient hours. Still he refused to give it up and go to work for another company. We had a wonderful week together and then I returned to the US. I again met Benno in 1992 when my wife and I were travelling in Italy on vacation. His situation hadn't changed. We had a nice visit and did some sight seeing with him before we left.

The Legacy remains

I started thinking about Benno recently after I visited a small power supply company on Long Island. What made me think of him was his winding order form. I saw a replica of it at the company I was visiting. The reality is that Benno's design formulas and forms have spread to almost all the local power supply companies in this area. His legacy remains. There are many engineers today using Benno's formulas and concepts and not knowing their source.

My favorite memory of Benno occurred when I was standing beside him in the Vatican. An orchestra visiting from Germany was playing a Beethoven piece and Benno's eyes started to tear. He looked at me and said the last time he was with his mother (just before her death) they were at a concert listening to this same piece. I am not sure where Benno is today, but I do know that I owe a lot to this unique and brilliant engineer, who fortuitously crossed my path in life and left it richer.

Frank Greenhalgh

June 11, 1999

He co-founded CEAG Electric Corporation (now ABB CEAG) and developed the first mainframe power system using the droop paralleling concept. He has written numerous articles and columns, presented papers at the milestone PowerCon convention and consulted for ABB CEAG and other companies. Recently his accomplishments include the development of two Web sites, www.fgl.com with the Power Corner and www.amityville.com. Frank is presently functioning as "Director of Technical Sales" for Toritsu Tsushin Kogoyo Corp.