Light Dimmer
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Posts: 46,084
Good folks on this board have helped before and I am sure it has not
changed.
My project includes a Stamp controlled dimmer for several lights
changing the intensity at defined intervals. I am using the PWM
command to vary an LED and with a MOSFET a small 12 volt bulb with
success.
I have tried using a MOC3010 Optocoupler and Triac driving 110vac
bulb but the light just comes on and off.
Should I stick with 12v or does some one have the cure?
Thanks,
Kirk
kwasson1@s...
changed.
My project includes a Stamp controlled dimmer for several lights
changing the intensity at defined intervals. I am using the PWM
command to vary an LED and with a MOSFET a small 12 volt bulb with
success.
I have tried using a MOC3010 Optocoupler and Triac driving 110vac
bulb but the light just comes on and off.
Should I stick with 12v or does some one have the cure?
Thanks,
Kirk
kwasson1@s...
Comments
gated with AC.
Kirk Wasson <kwasson@y...> wrote:Good folks on this board have helped
before and I am sure it has not
changed.
My project includes a Stamp controlled dimmer for several lights
changing the intensity at defined intervals. I am using the PWM
command to vary an LED and with a MOSFET a small 12 volt bulb with
success.
I have tried using a MOC3010 Optocoupler and Triac driving 110vac
bulb but the light just comes on and off.
Should I stick with 12v or does some one have the cure?
Thanks,
Kirk
kwasson1@s...
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[noparse][[/noparse]Non-text portions of this message have been removed]
When dimming with AC you need to find the 0 voltage Crossing, so you can
trigger the Triac.
If you want to use higher power lamps, having everything isolated from the
BS, add one opto for the Triac, and another opto for the 0 crossing.
This way, you have a pulse everytime the sine wave is crossing 0. Hence, you
need to trigger the Triac here.
You can use PWM at will, minding you trigger the Triac when the Sine is at
0.
Dealling with DC is straight forward. Just make sure the PWM has a frequency
lower than the RC of the bulb.
Or else the bulb is always on.
regards,
Antonio Sergio Sena
Antonio Sergio Sena
(Field Applications Engineer)
Primetec - Engenharia de Sistemas, Lda.
Rua Porto Alegre, 9 - 1º Esq.
2780-031 Oeiras
PORTUGAL
e-mail: asena@p...
WEB: www.primetec.pt
.
> Good folks on this board have helped before and I am sure it has not
> changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac
> bulb but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure?
> Thanks,
> Kirk
> kwasson1@s...
>
>
>
>
> 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
>
>
>
>
>
>
>
>
DC light if you vary the duty cycle of the output, which if amplified to 12
volt level of sufficient current will certainly dim a 12 V DC bulb.
But Triacs don't work that way. A Triac can be turned on anywhere within the
60 Hz AC cycle, but turn themselves off when the AC swings through zero
volts 120 times every second. AC dimmers work by triggering the triac "on"
earlier or later in the cycle. Trigger them on very early within the cycle
and the light is at near full intensity. Trigger them on halfway through,
and the light is on at 50 percent intensity. Trigger them on near the end of
the AC cycle and the light will be low in intensity. So essentially, you
need to phase-lock to the 60 Hz line frequency.
Mike Sokol
mike@f...
www.fitsandstarts.com
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "Kirk Wasson" <kwasson@y...>
To: <basicstamps@yahoogroups.com>
Sent: Wednesday, March 31, 2004 8:13 PM
Subject: [noparse][[/noparse]basicstamps] Light Dimmer
> Good folks on this board have helped before and I am sure it has not
> changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac
> bulb but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure?
> Thanks,
> Kirk
> kwasson1@s...
>
>
>
>
> 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
>
>
>
>
>
>
>
swtich on at some period after it (and before the next zero cross). The
later into the cycle you switch on, the dimmer the bulb will be. What
this means is that varying the intensity of the LED side of an
opto-triac will not dim your AC bulb.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: Kirk Wasson [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=OeHxNh0fWqUoOG2FPs_QfY_ed3-3_QxG07-wESEuap2qeEVY5KimhY4hS_oj88DDeCcqiaepxG8v7S71]kwasson@y...[/url
Sent: Wednesday, March 31, 2004 7:13 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Light Dimmer
Good folks on this board have helped before and I am sure it has not
changed.
My project includes a Stamp controlled dimmer for several lights
changing the intensity at defined intervals. I am using the PWM
command to vary an LED and with a MOSFET a small 12 volt bulb with
success.
I have tried using a MOC3010 Optocoupler and Triac driving 110vac
bulb but the light just comes on and off.
Should I stick with 12v or does some one have the cure?
Thanks,
Kirk
kwasson1@s...
dimming purpose. They lack interrupt capability. And they lack
precise timing in microsecond range, smallest resolution being 1 ms.
If anyone has controlled triac with BS2 for light dimming purpose, I
would be very interested myself.
Gracias.
--- In basicstamps@yahoogroups.com, "Kirk Wasson" <kwasson@y...>
wrote:
> Good folks on this board have helped before and I am sure it has
not
> changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac
> bulb but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure?
> Thanks,
> Kirk
> kwasson1@s...
through a resistor. This forms an integrator. The Voltage across the
capacitor then should go to the gate of a fet. The fet would drive the
optocoupler. This is simple. The integrator will give you an average
Voltage based upon the pulsewidth out of the BS2. The average Voltage would
linearize the value, and slightly turn on the triac.
Simple<G>.
Original Message
From: yellowniter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rKvgvpbfaF-L_bZjrrKHPFmTrZnHthU1Y5HFdiTpxP8rBRkHvhOlPMoHdMSjwb8eyOz_3cFcDSbZfrszXA]yellowniter@y...[/url
Sent: Thursday, April 01, 2004 1:26 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: Light Dimmer
I don't think you can use any of BS2 to control triac for light
dimming purpose. They lack interrupt capability. And they lack
precise timing in microsecond range, smallest resolution being 1 ms.
If anyone has controlled triac with BS2 for light dimming purpose, I
would be very interested myself.
Gracias.
--- In basicstamps@yahoogroups.com, "Kirk Wasson" <kwasson@y...>
wrote:
> Good folks on this board have helped before and I am sure it has
not
> changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac
> bulb but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure? Thanks,
> Kirk
> kwasson1@s...
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load.
On Wed, 31 Mar 2004, PHILIP GAMBLIN wrote:
> When I Googled triac, I found several example circuits. They all seem to to be
gated with AC.
>
> Kirk Wasson <kwasson@y...> wrote:Good folks on this board have helped
before and I am sure it has not
> changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac
> bulb but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure?
> Thanks,
> Kirk
> kwasson1@s...
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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of the message will be ignored.
>
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>
>
>
>
>
>
>
> Do you Yahoo!?
> Yahoo! Small Business $15K Web Design Giveaway - Enter today
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>
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>
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"Do not fear mistakes, There Are None" - Miles Davis
triac will turn on later than it would normally. Standard wall lamp dimmer
type stuff.
Original Message
From: Sean T. Lamont .lost. [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=_5fx4pVXP212meoqr-Vmpt5z9lRADbXg9wYQC6qNVSRycZjzgrN22QgnITp7qGG7LDsN6m1p5LvA4-fQTPc]lamont@a...[/url
Sent: Thursday, April 01, 2004 2:35 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Light Dimmer
Really? The only ones I've used have been gated with DC, switching an AC
load.
On Wed, 31 Mar 2004, PHILIP GAMBLIN wrote:
> When I Googled triac, I found several example circuits. They all seem
> to to be gated with AC.
>
> Kirk Wasson <kwasson@y...> wrote:Good folks on this board have
> helped before and I am sure it has not changed.
>
> My project includes a Stamp controlled dimmer for several lights
> changing the intensity at defined intervals. I am using the PWM
> command to vary an LED and with a MOSFET a small 12 volt bulb with
> success.
>
> I have tried using a MOC3010 Optocoupler and Triac driving 110vac bulb
> but the light just comes on and off.
>
> Should I stick with 12v or does some one have the cure? Thanks,
> Kirk
> kwasson1@s...
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
> Do you Yahoo!?
> Yahoo! Small Business $15K Web Design Giveaway - Enter today
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>
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>
Sean T. Lamont, CTO / Chief NetNerd, Abstract Software, Inc. (ServNet)
Seattle - Bellingham - Vancouver - Portland - Everett - Tacoma - Bremerton
email: lamont@a... WWW: http://www.serv.net
"Do not fear mistakes, There Are None" - Miles Davis
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makes perfect sense. I guess if the PWM pulse could
be synchronized with the AC it would work. In fact I
order a AWC Pak-Vc 8 channel PWM, IRF540 Mosfets and
TC1427 drivers. I will use 12v bulbs which should give
me plenty of light. I am also working on the power
supply.
Thanks, Kirk
--- "Sean T. Lamont .lost."
<lamont@a...> wrote:
>
> Really? The only ones I've used have been gated with
> DC, switching an AC
> load.
>
> On Wed, 31 Mar 2004, PHILIP GAMBLIN wrote:
>
> > When I Googled triac, I found several example
> circuits. They all seem to to be gated with AC.
> >
> > Kirk Wasson <kwasson@y...> wrote:Good folks
> on this board have helped before and I am sure it
> has not
> > changed.
> >
> > My project includes a Stamp controlled dimmer for
> several lights
> > changing the intensity at defined intervals. I am
> using the PWM
> > command to vary an LED and with a MOSFET a small
> 12 volt bulb with
> > success.
> >
> > I have tried using a MOC3010 Optocoupler and Triac
> driving 110vac
> > bulb but the light just comes on and off.
> >
> > Should I stick with 12v or does some one have the
> cure?
> > Thanks,
> > Kirk
> > kwasson1@s...
> >
> >
> >
> >
> > 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
> >
> >
> >
> >
> >
> >
> >
> >
> > Do you Yahoo!?
> > Yahoo! Small Business $15K Web Design Giveaway -
> Enter today
> >
> > [noparse][[/noparse]Non-text portions of this message have been
> removed]
> >
> >
> >
> > 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
> >
> >
> >
> >
> >
> >
>
> Sean T. Lamont, CTO / Chief NetNerd, Abstract
> Software, Inc. (ServNet)
> Seattle - Bellingham - Vancouver - Portland -
> Everett - Tacoma - Bremerton
> email: lamont@a... WWW:
> http://www.serv.net
> "Do not fear mistakes, There Are None" -
> Miles Davis
>
>
>
> To UNSUBSCRIBE, just send mail to:
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it will latch until the next zero crossing.
The trick is to look for the zero crossing point and then delay 8.333...
milliseconds for zero light, and shorter delays for closer
to full, with zero delay=100%.
Pulse width need only be a microsecond or less for most triacs, so the BS2sx
would be my first choice.
KF4HAZ - Lonnie
From: "Kirk Wasson" <kwasson1@s
> I want to thank everyone for the great advice. It
> makes perfect sense. I guess if the PWM pulse could
> be synchronized with the AC it would work. In fact I
> order a AWC Pak-Vc 8 channel PWM, IRF540 Mosfets and
> TC1427 drivers. I will use 12v bulbs which should give
> me plenty of light. I am also working on the power
> supply.
> Thanks, Kirk
>
>
> --- "Sean T. Lamont .lost."
> <lamont@a...> wrote:
> >
> > Really? The only ones I've used have been gated with
> > DC, switching an AC
> > load.
> >
> > On Wed, 31 Mar 2004, PHILIP GAMBLIN wrote:
> >
> > > When I Googled triac, I found several example
> > circuits. They all seem to to be gated with AC.
> > >
> > > Kirk Wasson <kwasson@y...> wrote:Good folks
> > on this board have helped before and I am sure it
> > has not
> > > changed.
> > >
> > > My project includes a Stamp controlled dimmer for
> > several lights
> > > changing the intensity at defined intervals. I am
> > using the PWM
> > > command to vary an LED and with a MOSFET a small
> > 12 volt bulb with
> > > success.
> > >
> > > I have tried using a MOC3010 Optocoupler and Triac
> > driving 110vac
> > > bulb but the light just comes on and off.
> > >
> > > Should I stick with 12v or does some one have the
> > cure?
> > > Thanks,
> > > Kirk
> > > kwasson1@s...
> > >
> >
> > Sean T. Lamont, CTO / Chief NetNerd, Abstract
> > Software, Inc. (ServNet)
> > Seattle - Bellingham - Vancouver - Portland -
> > Everett - Tacoma - Bremerton
> > email: lamont@a... WWW:
> > http://www.serv.net
> > "Do not fear mistakes, There Are None" -
> > Miles Davis
If you applied a pulse to a Triac every time the AC voltage goes thru
zero, you accomplished nothing. the lamp will stays ON for ever.
The dimming occurs when you apply a pulse some time after the AC
voltage have been zero.
Once the Triac goes ON, stays ON until the AC voltage goes thru zero.
Therefore, by varying the delay between 0 and 8.33 milliseconds (60 HZ
in the US) you vary the lamp intensity from zero to maximun.
You can also vary the lamp intensity by skipping cycles (or half cycles).
a solution. You will however need to replace the VR1 with a 0-5V
signal from the Stamp.
br
Lars
--- In basicstamps@yahoogroups.com, "yellowniter" <yellowniter@y...>
wrote:
> I don't think you can use any of BS2 to control triac for light
> dimming purpose. They lack interrupt capability. And they lack
> precise timing in microsecond range, smallest resolution being 1
ms.
>
> If anyone has controlled triac with BS2 for light dimming purpose,
I
> would be very interested myself.
>
> Gracias.
>
> --- In basicstamps@yahoogroups.com, "Kirk Wasson" <kwasson@y...>
> wrote:
> > Good folks on this board have helped before and I am sure it has
> not
> > changed.
> >
> > My project includes a Stamp controlled dimmer for several lights
> > changing the intensity at defined intervals. I am using the PWM
> > command to vary an LED and with a MOSFET a small 12 volt bulb
with
> > success.
> >
> > I have tried using a MOC3010 Optocoupler and Triac driving
110vac
> > bulb but the light just comes on and off.
> >
> > Should I stick with 12v or does some one have the cure?
> > Thanks,
> > Kirk
> > kwasson1@s...
> zero, you accomplished nothing. the lamp will stays ON for ever.
> The dimming occurs when you apply a pulse some time after the AC
> voltage have been zero.
> Once the Triac goes ON, stays ON until the AC voltage goes thru zero.
> Therefore, by varying the delay between 0 and 8.33 milliseconds (60 HZ
> in the US) you vary the lamp intensity from zero to maximun.
> You can also vary the lamp intensity by skipping cycles (or half cycles).
About a year ago someone mentioned a device like a TRIAC that always turns
on at the zero crossing and stay's on until it's triggered to turn off. He
had used it to make a "quieter" light dimmer. I don't remember what it was
called thou.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)
a while, but the technologies haven't changed too much in 20 years.
There no such thing as a quiet Triac light dimmer. Of course as many of you
have pointed out, a zero-crossover Solid State Relay turns on only when the
line AC is at zero. But that won't dim... it's only on and off. Triac
dimmers work by turning on later or earlier in the cycle. The only way to
make a dimmer quiet is to add a big inductor in series with the live AC
voltage feeding the light bulb. This will slow down the rise-time of the
current, and reduce the RF considerably.
One way to make a stamp do this is to make a sync to line signal and start a
timer running. I used to do this work via a 12-Volt step-down transformer
with a resistor in series feeding a zener diode. Makes a nice square wave
very close to the beginning of the 60 Hz cycle. Then you just start a
countdown clock running, so triggering immediately will make 100% light, and
triggering some 8 milliseconds later will be almost off. Since my 13 year
old boy is interested in controlling lights, I might cobble something
together and get him to program it for the Stamp. Anyone interested in the
support wiring to make this happen.
Mike Sokol
mike@f...
www.fitsandstarts.com
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "George Warner" <geowar@a...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, April 12, 2004 1:50 PM
Subject: [noparse][[/noparse]basicstamps] Re: Light Dimmer
> > If you applied a pulse to a Triac every time the AC voltage goes thru
> > zero, you accomplished nothing. the lamp will stays ON for ever.
> > The dimming occurs when you apply a pulse some time after the AC
> > voltage have been zero.
> > Once the Triac goes ON, stays ON until the AC voltage goes thru zero.
> > Therefore, by varying the delay between 0 and 8.33 milliseconds (60 HZ
> > in the US) you vary the lamp intensity from zero to maximun.
> > You can also vary the lamp intensity by skipping cycles (or half
cycles).
>
> About a year ago someone mentioned a device like a TRIAC that always turns
> on at the zero crossing and stay's on until it's triggered to turn off. He
> had used it to make a "quieter" light dimmer. I don't remember what it was
> called thou.
>
> --
> Enjoy,
> George Warner,
> Schizophrenic Optimization Scientists
> Apple Developer Technical Support (DTS)
>
>
>
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>
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>
>
>
>
>
>
>
them OFF before the AC voltage goes thru zero.
Some years ago was a device called Gate Turn OFF which work like a SCR
but could be turn OFF by applying a negative charge between Gate and
Cathode large enough to interrupt the conduction channel Anode to Cathode.
I do not think they make those devices anymore.