Why I started Unique3phase:

     My story starts when I bought a used 10 hp Invincible Vacuum Cleaner (now Gardner Denver Corp.) in the early 90’s. This vacuum was a fantastic deal and I just needed to use it a few hours a week.

Hard to start Industrial Vacuum cleaner
Gardner-Denver Invincible brand industrial vacuum

     To make a long story short, a sales rep brought a 25 hp rotary converter out to my shop and almost burned out my motor. He couldn’t get it to run and claimed I needed a bigger rotary. It would ramp up to about half speed and get no higher. The shop filled with the smell of burning insulation. He started talking about a 30 to 50 horse upgrade. It seemed so foolish to be trying to use a 50 hp motor just to run a 10 hp one.

     My father was an electronic engineer and I knew about electricity having worked with it growing up. Common sense told me that the approach he was using was not practical. The idea of hooking up an extra large three phase motor in the hopes of being able to get a smaller three phase motor started, was not the right science. 

How does the rotary converter work? 

     Think of how the rotary converter works. Do you think it is some sort of magic machine? That somewhere in the heart of this big idler motor lurks a hidden force just waiting to zap power into your load motor? No, that is not the case. There’s no secret hidden force inside the three phase motor. It’s just a motor. Motor manufacturers built it to run machines. It gets it’s power from outside itself, the power company, it wasn’t made to be a generator of three phase. This is why it is a weak feeble solution. In order to work it has to be way over sized, so that enough power can be siphoned off, to run the real motor.


But there was another way. The transformer converter. Before the rotary converter was popular there was the transformer converter. Developed over 60 years ago it uses a transformer and capacitors to provide the kick, the power, the nitrous oxide, to start a heavily loaded motor and enable it to drive a load at full power.

     I wanted to run that vacuum so I spent the next year searching library’s, looking for a solution. That’s when I found the transformer converter.

     You may be wondering why you haven’t heard of it?

     I wondered that myself, especially after I built one and found that it started the vacuum up like a dream. A quick fast start, with great amps and volts balance, and no noisy wasteful idler motor*.
Instead of a monster 40 hp rotary converter motor filling the shop with noise and heat, I had a small, silent, modified three phase transformer. I got so excited that I bought some more three phase things and ran them all off my transformer converter.

     I thought everyone should have a transformer converter.

     But out of all the converter manufacturers, there was only one making them, Ronk Electric Company. As time went by, I realized that the transformer converter was not pushed by manufacturers for a couple of reasons related not to the performance, but for practical business reasons.

     The rotary converter is a lot easier to sell to the average non-technical person who needs three phase. It offered manufacturers a machine that was more ‘plug and play’, with less knowledge required from the end user.

     The ad copy could read “Have three phase at home – just connect to your power panel and run all your machines.” There would be no adjustments that the customer would have to make. There would be no need for the customer to have amp and volt meters, or even know about amps and volts; just turn it on and run your motors.

American Rotary Ad copy
Ad From American Rotary Converter Company

     The secret to covering up the rotary’s weakness was to sell you a bigger rotary converter. The bigger the rotary converter they sell you, the more chance that it will start your motors, with the additional benefit of boosting their bottom line.

     Just because these rotary converters need no user adjustments and come prepackaged to work out of the box, doesn’t mean it’s the best for every machine. To me it is a compromise based on how easy it is for them to sell and how easy it is for the customer to install. As in my story of the vacuum cleaner, they wanted me to purchase an expensive over sized unit.

     After using my transformer converter for a few years I decided that I should publicize the transformer converter. I made up a little booklet and sold it in the back of Hemming’s Motor News magazine. After a while we moved and I sort of forgot about three phase for a while. Then in 2005 I made an instructional dvd showing people how to build the DIY converters; the transformer converter and the rotary converter.  I also had found a way to modify commercial transformers and even showed people how to make their own transformers. I sold this on eBay and my own website for years. For the couple of years I sold on eBay I got over 900 positive feedbacks.

     After selling my instructional materials to people all around the world do I still believe the transformer converter is the only way to go?

     No, you need to know what you want to run. Then make an informed decision. There are new developments in the technology that you should be aware of as you are planning your shop setup.   

     For the complete story on the different ways you now have to run three phase machines see this page here.  Various options for running three phase motors.

 * I say wasteful here in referring to the idler motor used in the rotary converter. But, I wanted to be absolutely fair and I did many tests using a regular household power meter. I show a whole lot of situations with rotary converters and how much they actually waste. I must admit that they are not as waste full as you might think. Mainly because the household electric meter can not measure reactive power. You can see the videos I did on this at my You tube channel here. 

front cover of unique3phase book
My book on Amazon