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Old 11th November 2004, 05:35 PM   (permalink)
Default Lets try again ! I need help with a follow on circuit

I'm working on 110v with five light channels
Please see drawing that someone kindly made for me on this site.

I have matrix switching using relays,

Has anyone got a circuit to replace the relays with triac or triac type devices.

if you could point me in the right direction like a site with information.

Please don't say keep looking through google, call me supid if you like, but someone out there knows how to do this, I just need a bit of help.

Thank you
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freddie belmont is offline  
Old 11th November 2004, 08:29 PM   (permalink)
Default

How are you going to control the switching of the Triacs?
Also, what wattage of lights are you going to be using?
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To the pessimist, the glass is half empty.
To the engineer, the glass is twice as big as it needs to be.
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Old 12th November 2004, 03:47 PM   (permalink)
Default chaser & power

A five channel chaser based around 4017
Simple Back and forth running. give the effects in the light boxes.

the wattage is 300 watts.

Can you help

Thank you
Freddie
freddie belmont is offline  
Old 12th November 2004, 03:56 PM   (permalink)
Default triacs

I've been using a 555 to control the relay's switching.
Maybe I could use the same or something with a slight time delay, for the triacs, so they switch off before the next set switch on.


I'm not sure at present it will be a bit of trial and error.


All the best
Freddie
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Old 13th November 2004, 03:19 PM   (permalink)
Default

Freddie,
Pardon me for thinking!!
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k7elp60 is offline  
Old 13th November 2004, 08:12 PM   (permalink)
Default thank you BUT

I already have the 5 channel chaser working through triacs.

No trouble there!

What im using to switch live to neurals and neurale to lives at the same time are relays THIS IS THE FOLLOW ON CIRCUIT I'M TRYING TO REPLACE
DOUBLE POLE DOUBLE THROUGH RELAYS

Is there a way of using Triac or triac type devices
that's the question?

All the best
Freddie
freddie belmont is offline  
Old 13th November 2004, 08:38 PM   (permalink)
Default

No. The triac can also firing with high slew-rate (dU/dt) between MT1 and MT2 (without gate triggering). Need redesigning the circuit.
Sebi is offline  
Old 13th November 2004, 09:39 PM   (permalink)
Default please read and think before you answer- thanks

I have 2 light boxes a 5channel chaser going forwards and backwards

wired 1,2,3,4,5 live A,B,C,D,E, WIRED NEUTRAL on a 5 channel chaser

Effect Lights look as if there going round in a circle

SWITCHED THE OTHER WAY ROUND

1,2,3,4,5 NEUTARL A,B,C,D,E ON THE CHASER

The effect is the lights going in and out the boxes


The chaser is working with triacs,


the relays i'm using work fine.

HERE GOES: I WANT TO KNOW IS THERE A WAY!
I CAN REPLACE THE RELAY CIRCUIT
WITH ANOTHER CIRCUIT THAT WORKS USING TRIAC OR TRYAC TYPE DIVICES,

REPLACING THE DOUBLE POLE DOUBLE THROUGH RELAYS



IF THERE IS A WAY DO YOU KNOW HOW I CAN DO IT!

I HAVE LOOKED THROUGH LOADS OF WEB SITES BUT I DON'T KNOW HOW TO DO IT. (I'M STILL LEARNING)

THATS WHY I'M ASKING FOR HELP

IF YOU CAN'T HELP DON'T WRITE, IT JUST CLUTTERS THINGS UP,

BUT IF YOU HAVE SUGGESTIONS I'M OPEN TO THEM!

If what i'm suggesting won't work in practice and you know that,
I also would find that of help, so i'm not wasting yours or my time.

Thank you for your time

Freddie
freddie belmont is offline  
Old 13th November 2004, 10:16 PM   (permalink)
Default

http://www.littelfuse.com/cgi-bin/r....l?SeriesID=603
peeks in
a quadrac might work
Quote:
The Quadrac device is a bidirectional AC switch and is gate controlled for either polarity of main terminal voltage. Its primary purpose is for AC switching and phase control applications such as speed controls, temperature modulation controls, and lighting controls where noise immunity is required
williB is offline  
Old 13th November 2004, 10:20 PM   (permalink)
Default

One thing you may want to think about is designing into the circuit what is called "keep-warm" or "soft-start". When using regular incandescent lamps, there is a large inrush current while the filiament is cold, this can produce very large short term current draws. Especially when many lamps are turning on at the same time. This does 2 things, one, it is hard on the lamp and shortens its life, and two, it can produce alot of electrical noise that Triacs are not going to like, causing dv/dt false triggering that Sebi mentioned.

Often lamps in this type of arrangement are constantly powered at a very low level, just enough to keep the filiament "warm". This stops the mechanical shock to the filiament when the lamp is powered, and greatly reduces the inrush current of a cold filiament.

Sometimes, depending on the lamps used, or the flash rate, the lamps filiament does this on its own if it is flashing fast enough to never really cool off.

All of the lamp driver circuits I use at work include a keep-warm and soft start design by way of PWM ( Pulse Width Modulation ). Since the stuff I do involves DC, the circuits are not of much use to you, but the same principles apply to AC lighting.

There are many circuits available for doing what you want, and at the risk of getting the Trout Slap for posting a link for another site :lol: when there are likely some here, here you are:

http://www.epanorama.net/documents/l...ghtdimmer.html

this link has some good basic info, and explains triacs, keep warm, etc
zevon8 is offline  
Old 13th November 2004, 10:29 PM   (permalink)
Default

i havent worked out just how it would work yet, but you might need four to replace each relay you are using now..

Quote:
Trout Slap
lol
rushes out..
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