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if you plan to use more than one Triac you have to use one of the electricalisolations technique between the first and the second triggering circuit, i.e. you can't connectboth them directly to the same triggering circuit.
I think the isolation required,
do not forget that the Triac contain to SCR with Inverse-Parallel connection,
when you plan to firing many SCR from the same firing cct. you need to use electrical isolation,
which you can provide it by using Pulse Transformer.
Funny, anyway let me explain that to u, and before I do that,but in your mind, I have good info. about the practically using of the SCR and Triac, because I teach both them in the P.E. Lab, and I studied it for more then a year when I was student, after all I do not like to comments on your statements, I will just explain some things.
Hi i was able to successfully complete it.here are some photos
Hi,Quote from: aruna1 on April 07, 2010, 11:44:42 PMHi i was able to successfully complete it.here are some photos Great But... Why 3 trimmers?
Hmmm, do you know something, why do you think you have more knowledge than other people???
the design of the triggering circuit with pulse transformer is the best, you have to accept that.
addition to that, who you are in order to talk about my informations, what's you background?? sorry did you finished inMIT or Harvard!!!!
otherwise, let us say you have good info in Triac, that's not mean you are the king of electronics!!!
at last I do not like to discuss people do not know about the correct scientific discussions,
and the circuits which I teach it is designed by professor, who have more than 100 research in IEEE and other bigscientific magazines.
BTW, this circuit not accurate, how you can control in power in accuracy form???how you can give the correct firing angle??you still change in variable resistor to get what you want!!!!!! bad cct.
three trimmers for set 3 time selections 5min,10min and 15min.
by the way i have a question.is it ok to operate the circuit 24x7 ? i mean i continuously supply power to transformer and it will keep NE555 in standby mode so when i press the button it will switch on the relay and after time up it will switch off and go to standby.is there any danger in doing this or will this reduce life time of the unit?
Hi,Quote from: aruna1 on April 09, 2010, 10:05:06 AMthree trimmers for set 3 time selections 5min,10min and 15min.Ahh, OK.Quote from: aruna1 on April 09, 2010, 10:05:06 AMby the way i have a question.is it ok to operate the circuit 24x7 ? i mean i continuously supply power to transformer and it will keep NE555 in standby mode so when i press the button it will switch on the relay and after time up it will switch off and go to standby.is there any danger in doing this or will this reduce life time of the unit?A little hard to tell without knowing neither the circuit, nor the components selected, but if the transformer is build for it (might say something on the label on that) and the schematic is sensible with respect to handling the power in each, permanent power should give a longer life on most components. Electrolytic caps will die sooner when powered constantly, as they are kept warmer than else and so will dry out sooner, but the main issue is keeping the temperature down (and you can get 105°C electrolytes if needs be, regular ones are 85°C max and the high temperature caps will live longer, even at eg. 40°C).All semiconductors are more stressed by turning them on (inrush current is the sinner) than staying on.If you want a more specific review of your circuit, please post the schematic.
hi this is the basic circuit(only with one trimmer)
I don't think I have more knowledge than [all] other people, but I do know I have loads more knowledge than you, not only from here, but you have opened your mouth on Dutchforce as well for some ~3 years now.
Quote from: Abdulla M.A. on April 08, 2010, 06:02:02 AMthe design of the triggering circuit with pulse transformer is the best, you have to accept that.No I don't, try it and see for yourself. (Why do you think you know more than other people? )
First, my apologies to the remark on your earlier avatar by the way, it was not here but on Dutchforce that you started out with the fascistic skull and crossed machineguns (which really not added to your credibility).
I am a seasoned engineer who, as mentioned, have read you on Dutchforce as well and this alone gives me plenty of reason to be sceptic to what you say in general and besides I am perfectly able to "talk about your informations" alone on the grounds that you claim, that this circuit (that I have build more times than you have obviously even seen a TRIAC) don't work
I don't see the relevance of where I studied (it was in DK) in that, as you get the main part of your knowledge after graduating.Statistically speaking, around half of the persons graduating from any class is below average, even in Baghdad
You are the only one to ever call me that, so that's on your account. At most I have called my self "Sir N", but that's just to help people pronounce my name.
I cannot accept that you just claim that it doesn't work, as I have done it so many times.
Despite the discussion being started by your wrong postulate, you apparently just want me to say you are correct to call it a scientific discussion? Sorry, can't help you there.
Professors and teachers in general who's have their daily life in teaching faculties alone, are very often badly off the mark, lacking the grit of industrial designers, but that's not new... A lot of people consider "The Art of Electronics" as a "bible" in electronics, but it is flawed in several places and Wince Hill (one of the authors), while absolutely not stupid!, have been typical for this category of faculty teachers in a couple of debates I've had with him, even if he does have his own company for industrial design.People who can, do - and people who can't teach.Before you go further in this rather unscientific discussion, would it be possible to urge you to try paralleling two TRIACs the way I drew it and see for yourself?Or are you just completely unwilling to learn?
well D1 and D3to stop reverse voltage fed n to trigger pin and make trigger value 0 instantly and making it trigger it.before adding these diodes i had a problem of auto triggering at the moment relay switches off making it to turn on relay again.after adding these diodes i was able to stop that from happening.
it was stated in following tutorial http://physics.learnhub.com/lesson/5112-555-timer read under topic "Relay coils and other inductive loads"
i didn't go for a micro because they are very sensitive and easily burns out.
Hi,Quote from: aruna1 on April 09, 2010, 08:52:27 PMwell D1 and D3to stop reverse voltage fed n to trigger pin and make trigger value 0 instantly and making it trigger it.before adding these diodes i had a problem of auto triggering at the moment relay switches off making it to turn on relay again.after adding these diodes i was able to stop that from happening.OK, but it seems to be an odd way of accomplishing that. Take a look at how I would do it with a 555. It's larger than what you want, but I didn't go for small in particular, as I just meant it as a way to show you how to minimize noise - if you study both the schematic and the PCB, you'll see what would take numerous posts to describe in detail.Quote from: aruna1 on April 09, 2010, 08:52:27 PMit was stated in following tutorial http://physics.learnhub.com/lesson/5112-555-timer read under topic "Relay coils and other inductive loads"It describes the free wheeling diode over the relay clamps and a diode going from the output of the 555. A little different from when you use a transistor to drive it.You can see what I mean about the diodes in the schematic.Quote from: aruna1 on April 09, 2010, 08:52:27 PMi didn't go for a micro because they are very sensitive and easily burns out.Well, I have seen far more 555s die than micros, but that's probably because they're everywhere. If treated right, components doesn't burn out, but until embedded in a PCB, controllers are much more sensitive than an nMOS 555 (but that goes for MOSFETs and anything CMOS as well).However, you build, you choose
I know you was in Dutchforce, you run away for unknown reason, but I still there,
but you run away so, you still think that I have old info., dear, I changed from the time I entered the Dutchforce.
what are the purposes of C1,C6 , R2 and R5?
Hi,Quote from: aruna1 on April 10, 2010, 11:54:48 AMwhat are the purposes of C1,C6 , R2 and R5?C1 is for noise decoupling at the trigger pin.C6 is for snubbing what little of the flyback gets by D3 (An 1N4148 will take much more of the flyback than an 1N400x).R2 is protection of the capacitor draining transistor in the 555, that otherwise sees quite large currents from a 470µF cap.R5 is to close Q1 fast and reliable, as the nMOS 555 doesn't do a very good job of that.
No point in taking this any further, if you are so afraid of getting your fixed beliefs disproved, but don't claim you have learned a lot, when you take such stand in a matter where you could actually learn.
End of discussion, at least on my behalf - I can see why Dutchforce posts with the sole content being either "Chop", "Beam" or "Catch" really is more important than silly learning, but should you ever get around to spending a bit of your precious time on testing parallel TRIACs, we may reenter discussion. Until such time... I won't be wasting more time on you.