triacs can turn on when dv/dt is too great, try putting in a snubber network
like (and this is just a guess)

Motor lead-----L-------------
            |-C--|       |   Opto
                C            C   coupler
Neutral   -------------------

for some value of components this should work YMMV :) adjust font till it
makes (some) sense

         cya,   Andrew...




> -----Original Message-----
> From: Francois Robbertze [SMTP:fr10@PIXIE.CO.ZA]
> Sent: Friday, September 01, 2000 4:52 PM
> To:   PICLIST@MITVMA.MIT.EDU
> Subject:      Re: [PIC]: Switching a 220V AC Electric Bi Directional motor
> with a Triac/PIC
>
> Hallo again to all PicList members,
>
> I have difficulties switching a forward and reverse 220V AC bi directional
> motor with a pic, triacand optocoupler combination!
>
> The motor is a typical electric sliding gate opener motor - three wires -
> neutral, live(forward) and live(reverse) with a starting cap between
> forward
> and reverse.
>
> The obvious way is to use two relays. The one relay control the direction
> and the other one switch the current...
>
> I want to do it without relays!!!!
>
> I have connect  two MOC3011 optocouplers  and  two IT416  triac's to a pic
> to
> control this motor, but this configuration damage the two IT's......
> I can connect either forward or reverse, but not both!!
>
> (It seems like the back EMF from the oposite direction switch the motor on
> in the opposite direction as well and the motor just vibrates - not sure)
>
> Attached is a unscrambled version of the layout...
>
>
> Can someone help?
>
> Kindest regards
>
> Francois Robbertze
> fr10@mweb.co.za
>
>  << File: TRIAC.txt >>
The information transmitted is intended for the person or entity to
which it is addressed and may contain confidential and/or privileged
material. Any review, retransmission, dissemination, copying or other
use of, or taking any action in reliance upon, this information by
persons or entities other than the intended recipient is prohibited. If
you have received this in error, please contact the sender and delete
the material from your system. Utility Services Corporation (USC) is not
responsible for any changes made to the material other than those made
by USC or for the effect of the changes on the material s meaning.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.