building a 3 phase varable frequency drive

[ray stewart]

i would like to build a simple one
any sites. circuits. ect. much appricated
it would also be nice to be able to reverse it

[Tecstatic]

i would like to build a simple one
any sites. circuits. ect. much appricated
it would also be nice to be able to reverse it

Although your questions are short formulated, the work needed to make your wishes come true, is not a short term job.

If you want to keep it simple not able to reverse, take a look at a ready built inverter IC, eg. the Fairchild FSBS15CH60 used in washing machines for variable speed, cost approx. 15$. If your application does not require closed loop regulator, consider using Atmels inexpensive 8-bit Mega128 or AT90CAN128 having can bus interface. They can control the 6 transistors. Lots of support on the processors is available at:

AVR Freaks

The amount of SW needed for this is manageable.

Maybe you can find an IC generating the control signals for the inverter, then you can avoid the uController for a simple circuit.

If you need reversing, encoder and closed loop feedback, then you are facing a big project.

You have to build the MOSFET inverter stage yourself. That is no easy task if you have not tried it before. You also need a powerful 32-bit micro controller eg. the ARM9 controller from ST, STR911FAM42X6 also inexpensive.

I must warn you, the ARM9 is not a newbie project, no offense, as I don't know your skills.

Install Ubuntu (free on Ubuntu Home Page | Ubuntu) on an old PC and use all the free tools available for the development of electronic circuits.

Kicad for diagrams and PCB layout.
GNU GCC compiler for C or C++ programming
GNU GDB for debugging
Code::Blocks for SW IDE tool.
HW In Circuit Emulator for debugging the taget. (processer specific, not too expensive)

These free tools can be used for both controllers (except the processor specific ICEs)

Why try to develop free alternative energy with non-free tools costing a fortune ?

If you want the advanced solution, you need to gather a group joining forces, as this is a difficult task requiring much difficult work for one person, unless you are skilled in the art.

I have been through this, but don't count me in, 24/7 is a hard limit.

Eric

[amigo]

Here's a post with a circuit on OU forum - it's a 2 phase drive though...

Maybe you want to read the whole thread about the project (Tesla patent 382,282) as well.

Tesla Patent 382282, and all related to his transformers/converters

[ray stewart]

more idears the better

K.I.S.S any pree built drives for under $50 sounds great i dont want to re invent the wheal
or methods to modify scavengable drive systems like the drives in washing machines air conditioners etc
thanks for the responces so far

[patmac]

In some of my research I've using my PC to avoid to build complex circuits on protoboards, above all if I need control time, pulses width etc.

Old PC's has a very strong advantage you can USE THE PARALLEL PORT TO CONTROL CIRCUITS. it's very easy program it with C++ and is possible connect it directly to circuits and control MOSFET's transistors etc.

I protect the port with diodes, but for circuits inductives is better use opto insulators like 4N33 for example.

On Windows is very much easy by using Visual Basic Express for free on Microsoft page, only you need Windows License, is possible use it on our research without pay royalties if we no sell the software D:.

[Inquorate]

Lol

@patmac - never thought I'd see the day when the apple ceo recommended microsoft. but I console myself (pun) that the old pc you would use the printer port of, would probably not run the memory hungry visual basic.