How can I make a Ac to Ac converter with variable frequency?

I intend to make a devise where it would have an impute of 120v ac at 60Hz and have a output of 120v ac at a frequency between 10 and 60 Hz and could be changed with a variable resister in fine increments. this also needs to be able to handle 10 amps.   

any ideas, I would appreciate all help 

sort by: active | newest | oldest
jeff-o7 years ago
What you're asking is actually somewhat difficult to do.  In your case, the best solution is a variable frequency drive for AC motors.  Hopefully you can find a suitable one in your price range...
alexander.m (author)  jeff-o7 years ago
 well there is a retailer I found that has a link at the top of this page that offers vary expensive components. with all considered it would probable be best if I compromise and make a Dc system withe a rheostat 
Here's a kit that can handle 5.5 amps.  Same thing but cheaper.

And another, again only 500W @120V.

And here's an interesting circuit I found that uses a light dimmer IC.  No word on current capability, though.

Here are some professional motor controllers.

Aaaaand...  JACKPOT!!!!


Thanks for asking this question, by the way.  Now I'm interested in outfitting my drill press with a speed controller so I don't have to change belts anymore.
alexander.m (author)  jeff-o7 years ago
Thanks for the help the first one would be best for me. Speaking of drilling, I will give you some advice on drilling metal, you can increase your accuracy and the lifespan of your drills with center drill.They are used to make to make a small hole before you use regular drills with out this the end of a jobber bit will wonder and dull the end. You could get them at busy bee tools in mississauga they are worth the drive and every penny. 
busybeetools.ca/cgi-bin/homepage

You can apply an AC motor frequency inverter to adjust the voltage and frequency. Maybe you can take a look at these VFD drives:

http://goo.gl/ABeF6I

I think if you have to ask here, you don't understand the complexity of what you are trying to do. Buy one.

Steve
I was hoping you would have the answer, cause I'm interested in what it would take.

I can figure out part of it, or the other part of it but I can't figure out all of it at once.  Never mind the 10 amp req.
alexander.m (author)  Re-design7 years ago
 what I intend to do withe this is to make a speed controller for a single phase ac motor, from my research found that  thy run at 1720 rpm at 60 Hz and 1400 rpm at 50 Hz and at any lower frequency they will run at a lower speed. this would be perfect for my application things such as large rheostats will reduce the power and three phase and large dc motor are expensive and would require a more complex power supply. I have found some ac  motor controller online that I could order but there expensive a and only work with 3 phase motor. I have figured out a circuit that may work that uses two magnetic relays and a dc pulsing circuit to activate the relays. in theory this works the only problem is that the relays have a short delay and by having to activate and deactivate reputedly they might brake and short circuit. the only solution that I see is if the made KW transistors. 
 www.robotmarketplace.com/products/0-RELAY40.html  
Three phase motors are cheaper and lighter than single phase motors for a given power output.
lemonie7 years ago
You'd need to convert to DC then use an inverter.
Look for something like variable frequency motor control schematic
I'm not inclined to pick through an internet search, but maybe someone else would do that for you.

L