switching AC load problem
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Dear Sir,
In my project the BS2 control a solid state relay with zero crossing to
switch on/off 220VAC contactor.The user should press a push-button to start
the operation and then the contactor is switched off when the weight reading
match the setpoint.The problem is some times pressing the push-button
corrupts the transducer A/D operation and I have to press the key which
performs the initial conditions of the A/D again.
How can I solve this problem to guarantee proper operation?
There is 250V varistor across the main.
Thank You
Mohamed Refky
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In my project the BS2 control a solid state relay with zero crossing to
switch on/off 220VAC contactor.The user should press a push-button to start
the operation and then the contactor is switched off when the weight reading
match the setpoint.The problem is some times pressing the push-button
corrupts the transducer A/D operation and I have to press the key which
performs the initial conditions of the A/D again.
How can I solve this problem to guarantee proper operation?
There is 250V varistor across the main.
Thank You
Mohamed Refky
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp.
Comments
>In my project the BS2 control a solid state relay with zero crossing to
>switch on/off 220VAC contactor. The problem is some times pressing the
>push-button
>corrupts the transducer A/D operation and I have to press the key which
>performs the initial conditions of the A/D again.
>How can I solve this problem to guarantee proper operation?
>There is 250V varistor across the main.
Add another varistor right across the coil of the contatctor. If the
contatctor drives an inductive load, also consider adding varistors right
at the load.
dwayne
--
Dwayne Reid <dwayner@p...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax
Celebrating 18 years of Engineering Innovation (1984 - 2002)
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associated with starting a motor drop the voltage to your control
system ?
Have you tried (or are you) powering from a seperate and stabile
source ?
The lights in my house dim whenever the water pump starts. If a
dimmer is on a low setting it will often just turn off the light.
I found powering after a computer battery backup supply stops most of
the problems.
--- In basicstamps@y..., Dwayne Reid <dwayner@p...> wrote:
> At 12:30 PM 5/24/02 +0300, Mohamed REFKY wrote:
>
> >In my project the BS2 control a solid state relay with zero
crossing to
> >switch on/off 220VAC contactor. The problem is some times pressing
the
> >push-button
> >corrupts the transducer A/D operation and I have to press the key
which
> >performs the initial conditions of the A/D again.
> >How can I solve this problem to guarantee proper operation?
> >There is 250V varistor across the main.
>
> Add another varistor right across the coil of the contatctor. If
the
> contatctor drives an inductive load, also consider adding varistors
right
> at the load.
>
> dwayne
>
> --
> Dwayne Reid <dwayner@p...>
> Trinity Electronics Systems Ltd Edmonton, AB, CANADA
> (780) 489-3199 voice (780) 487-6397 fax
>
> Celebrating 18 years of Engineering Innovation (1984 - 2002)
> .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
> `-' `-' `-' `-' `-' `-' `-' `-' `-'
> Do NOT send unsolicited commercial email to this email address.
> This message neither grants consent to receive unsolicited
> commercial email nor is intended to solicit commercial email.
an high inductive load as a contactor coil.
Regards
ECO
Original Message
From: "Mohamed REFKY" <refky@h...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, May 24, 2002 11:30 AM
Subject: [noparse][[/noparse]basicstamps] switching AC load problem
>
> Dear Sir,
> In my project the BS2 control a solid state relay with zero crossing to
> switch on/off 220VAC contactor.The user should press a push-button to start
> the operation and then the contactor is switched off when the weight reading
> match the setpoint.The problem is some times pressing the push-button
> corrupts the transducer A/D operation and I have to press the key which
> performs the initial conditions of the A/D again.
> How can I solve this problem to guarantee proper operation?
> There is 250V varistor across the main.
>
> Thank You
> Mohamed Refky
>
>
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp.
>
>
> To UNSUBSCRIBE, just send mail to:
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of the message will be ignored.
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>
>
>
>Reply-To: basicstamps@yahoogroups.com
>To: <basicstamps@yahoogroups.com>
>Subject: Re: [noparse][[/noparse]basicstamps] switching AC load problem
>Date: Sat, 25 May 2002 10:10:02 +0200
>
>Not sure, but zero crossing should not be adequate to commute
>an high inductive load as a contactor coil.
>Regards
>ECO
Why not
What does a zero-crossing turn-on circuit refer to?
Zero-crossing turn-on and turn-off refer to the point on the AC wave form
when the voltage is zero. It is at this point that an AC SSR will turn on or
off. When the AC circuit voltage is at zero, no current is flowing. This
makes it much easier and safer for the semiconductor device in the relay to
be turned on or off. It also generates much less electrical EMI/RFI noise
>
Original Message
>From: "Mohamed REFKY" <refky@h...>
>To: <basicstamps@yahoogroups.com>
>Sent: Friday, May 24, 2002 11:30 AM
>Subject: [noparse][[/noparse]basicstamps] switching AC load problem
>
>
> >
> > Dear Sir,
> > In my project the BS2 control a solid state relay with zero crossing to
> > switch on/off 220VAC contactor.The user should press a push-button to
>start
> > the operation and then the contactor is switched off when the weight
>reading
> > match the setpoint.The problem is some times pressing the push-button
> > corrupts the transducer A/D operation and I have to press the key which
> > performs the initial conditions of the A/D again.
> > How can I solve this problem to guarantee proper operation?
> > There is 250V varistor across the main.
> >
> > Thank You
> > Mohamed Refky
> >
> >
> >
> > _________________________________________________________________
> > Get your FREE download of MSN Explorer at
>http://explorer.msn.com/intl.asp.
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
>and Body of the message will be ignored.
> >
> >
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>http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
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>
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voltage of 0 volts, but it turns off, if switched by a TRIAC or SCR when
the line current is zero. Because of the inductive characteristics of
the load, this point probably won't coincide with the zero crossing of
the line voltage. when you build a magnetic field up in a coil by
running current through it, it continues giving current back until that
field has collapsed. Just so you understand, the theory behind the
thing. Hope this helps and as always I am sure I have stated something
not quite correctly. I do this so that others can have their two cents
worth and the whole group can understand exactly what is going on.
HTH,
Leroy
Mohamed REFKY wrote:
>
> >From: "ECO" <ecourt@b...>
> >Reply-To: basicstamps@yahoogroups.com
> >To: <basicstamps@yahoogroups.com>
> >Subject: Re: [noparse][[/noparse]basicstamps] switching AC load problem
> >Date: Sat, 25 May 2002 10:10:02 +0200
> >
> >Not sure, but zero crossing should not be adequate to commute
> >an high inductive load as a contactor coil.
> >Regards
> >ECO
> Why not
> What does a zero-crossing turn-on circuit refer to?
> Zero-crossing turn-on and turn-off refer to the point on the AC wave form
> when the voltage is zero. It is at this point that an AC SSR will turn on or
> off. When the AC circuit voltage is at zero, no current is flowing. This
> makes it much easier and safer for the semiconductor device in the relay to
> be turned on or off. It also generates much less electrical EMI/RFI noise
>
> >
Original Message
> >From: "Mohamed REFKY" <refky@h...>
> >To: <basicstamps@yahoogroups.com>
> >Sent: Friday, May 24, 2002 11:30 AM
> >Subject: [noparse][[/noparse]basicstamps] switching AC load problem
> >
> >
> > >
> > > Dear Sir,
> > > In my project the BS2 control a solid state relay with zero crossing to
> > > switch on/off 220VAC contactor.The user should press a push-button to
> >start
> > > the operation and then the contactor is switched off when the weight
> >reading
> > > match the setpoint.The problem is some times pressing the push-button
> > > corrupts the transducer A/D operation and I have to press the key which
> > > performs the initial conditions of the A/D again.
> > > How can I solve this problem to guarantee proper operation?
> > > There is 250V varistor across the main.
> > >
> > > Thank You
> > > Mohamed Refky
> > >
> > >
> > >
> > > _________________________________________________________________
> > > Get your FREE download of MSN Explorer at
> >http://explorer.msn.com/intl.asp.
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
> >and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> >http://docs.yahoo.com/info/terms/
> > >
> > >
> > >
> >
> >
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> >from the same email address that you subscribed. Text in the Subject and
> >Body of the message will be ignored.
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
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