Re: [oopic] Re: Induction Motor control using ooPIC

I can't add much to this. Induction and brushless motors take a _lot_
of processing horsepower to do their job.

DLC

rtstofer wrote:
> --- In oopic@yahoogroups.com, "john.willium" <john.willium@...> wrote:
>
>> Hi Dennis,
>> I want to change the speed of the induction motor according to an
>> analog signal. I can give this signal to I/O line 1 to A/D conversion.
>> So according to the value (0-255), I want to change the speed of the
>> induction motor. For example, 100 rpm min & 1500 rpm max.
>>
>> The thing what I want to clarify is whether ooPIC can be used for this
>> purpose. Bcoz I'm familiar with ooPIC & know this is capable of
>> controlling servo motors.
>>
>> Regards,
>> John
>>
>
> You are trying to make a Variable Speed Drive (VSD) and this takes a
> LOT more electronics than an OOPic. Especially if the motor is more
> than a tiny fraction of a HP.
>
> You need to be able to create a square wave of appropriate voltage that
> varies in frequency from 3 to 60 Hz (90 - 1800 RPM 4-pole motor). This
> squarewave needs to be able to drive whatever current the motor
> requires.
>
> Normally this process goes: bring in AC, rectify it to DC, filter,
> switch to motor windings.
>
> Further, VFDs normally drive 3 phase motors although the second
> reference below shows driving single phase motors.
>
> There are references all over the place but here is one from Microchip:
> http://ww1.microchip.com/downloads/en/DeviceDoc/01033B%2041.pdf and
> http://ww1.microchip.com/downloads/en/AppNotes/AC%20Induction%20Motor%
> 2000984a.pdf
>
> See also
> http://www.aosmithmotors.com/html/motorDoctor/Understandingmotorspeed.ht
> m
>
> In the end, you won't be using an OOPic for this job.
>
> Richard
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>

--
------------------------------------------------------
Dennis Clark ooPIC Tech Support
www.oopic.com
------------------------------------------------------

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