triac
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Hello group, I'd like to make a light dimmer controlled by a stamp. does
anyone have a schematic/advice for doing this? I was thinking I could
hook up a triac to a pin and drive that with a square wave but can you
hook a triac directly up to a stamp like a transistor?
anyone have a schematic/advice for doing this? I was thinking I could
hook up a triac to a pin and drive that with a square wave but can you
hook a triac directly up to a stamp like a transistor?
Comments
over the brightness you need to delay turn-on of the triac after the
zero-cross, because once it's on, it stays on until the zero cross. It
might be easier to adapt a standard dimmer circuit and replace the
mechanical pot with one that can be digitally controlled by the BASIC
Stamp.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: mark allen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=AqQAuvob8Or70RtTWhHco5DEI4t-awrE1lcq1KPwQfQhniDNQDRPXl8DJsin75EBOC1Z5C8tSOP_VwD8Ag]m@m...[/url
Sent: Monday, June 21, 2004 6:23 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] triac
Hello group, I'd like to make a light dimmer controlled by a stamp. does
anyone have a schematic/advice for doing this? I was thinking I could
hook up a triac to a pin and drive that with a square wave but can you
hook a triac directly up to a stamp like a transistor?
wrote:
> It's not just enough to drive it with a square-wave, to have control
> over the brightness you need to delay turn-on of the triac after the
> zero-cross, because once it's on, it stays on until the zero
cross. It
> might be easier to adapt a standard dimmer circuit and replace the
> mechanical pot with one that can be digitally controlled by the
BASIC
> Stamp.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
Why not just use DC and a mosfet ? you don't need pure DC if all you
are doing is rectifing, and since you are talking about dimming, that
should not be too much of a problem.
If you missed that, rectifying AC into DC and then running a light or
something, will result in a lower voltage and a dimmer bulb. a
little filtering with some caps and you can get the brightness back
and maybe even better.
And, it is much easier to pulse a MOSFET for dimming.
Dave
Jon Williams
Parallax
Original Message
From: Dave Mucha [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DpJBIWWChbRApBqviJbHxVBle8T2T5JMfu4J4ywAa0q7tCh1FHVNp5zNX1rAblVEoAchqICOxRw]davemucha@j...[/url
Sent: Monday, June 21, 2004 7:27 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: triac
--- In basicstamps@yahoogroups.com, "Jon Williams" <jwilliams@p...>
wrote:
> It's not just enough to drive it with a square-wave, to have control
> over the brightness you need to delay turn-on of the triac after the
> zero-cross, because once it's on, it stays on until the zero
cross. It
> might be easier to adapt a standard dimmer circuit and replace the
> mechanical pot with one that can be digitally controlled by the
BASIC
> Stamp.
>
> -- Jon Williams
> -- Applications Engineer, Parallax
> -- Dallas Office
Why not just use DC and a mosfet ? you don't need pure DC if all you
are doing is rectifing, and since you are talking about dimming, that
should not be too much of a problem.
If you missed that, rectifying AC into DC and then running a light or
something, will result in a lower voltage and a dimmer bulb. a
little filtering with some caps and you can get the brightness back
and maybe even better.
And, it is much easier to pulse a MOSFET for dimming.
Dave
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>Hello group, I'd like to make a light dimmer controlled by a stamp. does
>anyone have a schematic/advice for doing this? I was thinking I could
>hook up a triac to a pin and drive that with a square wave but can you
>hook a triac directly up to a stamp like a transistor?
If you're looking to do this for use in a home, the simplest way is to use an X-10 dimmer and use the PBASIC XOUT command to control it. You will also need an X-10 interface as well.
Regards,
Bruce Bates
>To UNSUBSCRIBE, just send mail to:
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>
>Yahoo! Groups Links
>
>
>
>
> Hello group, I'd like to make a light dimmer controlled by a stamp.
does
> anyone have a schematic/advice for doing this? I was thinking I
could
> hook up a triac to a pin and drive that with a square wave but can
you
> hook a triac directly up to a stamp like a transistor?
Mark,
I don't think it is possible to control triac using Basic Stamp due
to its slow speed and lack of interrupt. I have not seen any such
design (and I've searched hard).
I have done a similar thing in the past, not directly connecting a Stamp to
a dimmer but I used the analog output voltage of a TDA8444. But a PWM from a
Stamp should do the same job.
I have then built a special type of optocoupler using a high impedance
photoresistor to replace the potmeter in the dimmer and a LED connected to
the output voltage. The LDR and de LED were glued together in a small dark
plastic casing (1 cm of a BIC ballpoint :-).
But be carefull, on the cicuit of a dimmer there is the full mains voltage
and you need a special type of LDR that keeps alive and happy with these
high voltages!!
My LDR was designed for 400 Volts peak to peak. But we have 230 Volts here.
This system has been running for years keeping the amount of light in my
working place at a constant level.
I hope this helps, but be VERY carefull !!
Klaus
Original Message
From: "basicstampede" <basicstampede@y...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, June 22, 2004 1:52 PM
Subject: [noparse][[/noparse]basicstamps] Re: triac
> --- In basicstamps@yahoogroups.com, mark allen <m@m...> wrote:
> > Hello group, I'd like to make a light dimmer controlled by a stamp.
> does
> > anyone have a schematic/advice for doing this? I was thinking I
> could
> > hook up a triac to a pin and drive that with a square wave but can
> you
> > hook a triac directly up to a stamp like a transistor?
>
> Mark,
>
> I don't think it is possible to control triac using Basic Stamp due
> to its slow speed and lack of interrupt. I have not seen any such
> design (and I've searched hard).
>
>
>
>
>
> 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.
>
> Yahoo! Groups Links
>
>
>
>
>
>
sending unit you connect to the Stamp, a lamp module,
and the recieving unit you plug into the wall,
and an RF remote for hand control -- all together
these cost $25.00, I believe. Such a deal.
--- In basicstamps@yahoogroups.com, Bruce Bates <bvbates@u...> wrote:
> At 04:23 PM 6/21/04 -0700, mark allen wrote:
> >Hello group, I'd like to make a light dimmer controlled by a
stamp. does
> >anyone have a schematic/advice for doing this? I was thinking I
could
> >hook up a triac to a pin and drive that with a square wave but can
you
> >hook a triac directly up to a stamp like a transistor?
>
> If you're looking to do this for use in a home, the simplest way is
to use an X-10 dimmer and use the PBASIC XOUT command to control
it. You will also need an X-10 interface as well.
>
> Regards,
>
> Bruce Bates
>
>
>
>
>
>
>
> >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.
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
wrote:
> MOSFETs won't work if you're looking to dim 120 VAC lights....
>
> Jon Williams
> Parallax
Of course not, but rectify the AC and you have DC.
And you can get a mosfet to dim 150 VDC.
And most light bulbs are incandescent and will work on either AC or
DC.
Dave
I have made a light dimmer using a triac controlled by a stamp. The stamp
interfaced to a 256 step digital pot (Dallas Semiconductor DS1267) using
the stamp's serial interface. The digital pot was used to control when to
turn on the triac during the AC cycle. I used a zero crossing detector to
create a pulse when the AC cycle crossed zero. The pulse from the zero
crossing detector would go to a one shot with the digital pot controlling
the delay of the one shot. The output of the one shot would drive an
optoisolator (MOC0310) which would drive the triac. By changing the tap
on the digital pot via the stamp you can control light intensity. Here
is a link to info on light dimmers.
http://www.epanorama.net/links/lights.html#dimbasic
Ron
mark allen <m@m...>
No Phone Info Available
06/21/2004 05:23 PM
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Subject: [noparse][[/noparse]basicstamps] triac
Hello group, I'd like to make a light dimmer controlled by a stamp. does
anyone have a schematic/advice for doing this? I was thinking I could
hook up a triac to a pin and drive that with a square wave but can you
hook a triac directly up to a stamp like a transistor?
To UNSUBSCRIBE, just send mail to:
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from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Yahoo! Groups Links
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