New Version 2

Note. This listing is for PLANS ONLY.

Build yourself a single to three phase rotary converter using my plans, and save money by not requiring an expensive transformer.

You can see it being demonstrated here --- https://vimeo.com/130990021

See for yourself how few components are required for this unconventional design. The video shows you the construction components, and then you will see it starting my 12” swing Harrison L6 lathe. This 2 HP lathe is not an easy one to start due to its gear head design; a well known 3KW static converter would not start it even on full output setting. There are many rotary converter designs to be found, but they either incorporate an expensive transformer, or they only provide an output at 230 volts. Whilst most modern electric motors can be configured for dual voltage operation, many older motors are either not easy, or impossible for either technical or practical reasons..

The first of these plans show the simple and well known 230 volt system, providing instructions and a circuit, and explaining which type of motor to use.

Secondly, information showing how the first type can be modified, using a suitable motor, to become a typical 230v to 415v RPC such as is supplied by a numbers of manufacturers, all of which require an expensive transformer.

Finally I give you technical description, full constructional details and circuit diagram for my new design.

In 2012 I spent four months developing the working result, meeting very many difficulties in the process. I explain all of these difficulties, and how I solved them. This design does NOT require the expensive transformer of the convention industrial models.

In 2015, I improved the design, using fewer components but with added overload protection.

Further minor improvements four more times.

You get details of how to choose the correct type of three phase motor, and how older, often more reliable motors can be modified if originally wired for one operating voltage only.

The importance of “phasing” the motor is explained, with explicit details of how it can be done.

The circuit I describe and the knowledge I bring to it is based on the UK 230 volt mains supply, and I can not advise on its suitability for other mains supply systems.

This second version has been constructed using only top quality new components, all of which were purchased through  Ebay usually at advantageous prices, unlike the first version which sourced all components from my junk box, except the slave motor (£15 from scrap yard), this motor being retained.

What do you get? 10 printed A4 sides include 7-1/2 pages of text plus the circuit diagrams. In the text I explain certain simple but necessary 3 phase induction motor facts which surprisingly few people (including many electricians) understand. I describe how to modify the more reliable old motors, detailing the “traps”. Search your local scrapyard KNOWING what to look for. The importance of the correct type of capacitors is explained, and the different ways of connecting them.

I have presented more important and practical info in these notes than I was able to find in two currently available books on rotary converters.

I have created an FAQ based on questions asked,  together with a full components list with costs to me. 

To receive these you MUST contact me by email on receipt of the documents. You will find my email at the end of the document.

I am continuing to improve and simplify the design; any such changes will appear in the FAQ.

I have researched some component suppliers and make this available to you.

I now also have a small stock of new and used components with which I may be able to assist you.

If you are competent and comfortable dealing with mains voltages, then YOU can build this quite cheaply.

If you are NOT competent, do NOT even consider it. Mains voltage circuits and electric motors are lethal in uncertain hands!

I will post to both UK and worldwide with the exception of South Africa and all of Southern African continent.