triac phase control 0-100%

[harp]

Trying to understand which properties of circuit affect triac phase range, is it possible to control near whole period, or it have some limitations - on net found a couple circuit, that claims almost full control, but in the past I build some simple circuit and remember that it do only half of control over triac?

[sam_sam_sam]

I hope that you are not trying to build up this circuit because you buy them already made
Here is an example of one type that is used in battery stud welders

100A Current Spot Welder Machine Time Control Digital Display Controller Board

https://www.ebay.com/itm/35458182072...Bk9SR868vp77Yw


Here is another one but this version has a control transformer which the one above dose not have but you have to add one

https://www.ebay.com/itm/28300956049...1001%26algo%3D

Here is another type

10000W SCR Digital Voltage Regulator Speed Control Dimmer Thermostat AC 220V US

https://www.ebay.com/itm/23506555387...Bk9SR5jq6J_7Yw

This is is the same type but it does not have a digital display

https://www.ebay.com/itm/17190706944...Bk9SR5rq6J_7Yw

I hope this helps help you this type of controller is meant for high transformer applications you can use them for incandescent light bulbs as well but it is over kill for this application

[harp]

Just something like that, but my question was about control circuit for triac

[harp]

Found some interesting information about triac

https://m.youtube.com/watch?v=jjTr7DD2ouE
TRIACs – The Dirty Details (3/3): Practical Considerations

Have someone knowngoodworking circuit for full control over triac (idealy 1-99%)

[stj]

there are different triacs that can switch at different points in the cycle.
it can get anoying when replacing faulty ones!

[harp]

What do I looking for? Have you some example?

[stj]

just read the datasheets, they refer to "quadrants" that is the low rising wave, the high rising wave, and the 2 halves as it falls.
here's some examples

[sam_sam_sam]

Found some interesting information about triac

https://m.youtube.com/watch?v=jjTr7DD2ouE
TRIACs – The Dirty Details (3/3): Practical Considerations

Have someone knowngoodworking circuit for full control over triac (idealy 1-99%)

Interesting video about how to use them

[harp]

just read the datasheets, they refer to "quadrants" that is the low rising wave, the high rising wave, and the 2 halves as it falls.
here's some examples

I look and steirs at datasheet... and nothing... I can not see how to determine what component is "better"... for different point of switching...

Anyway, all videos presents control triac in therir narrow midrange or so, I can not clearly see to one circuit that fully start at beginning after zero cross and control cutoff till end.

Now I found that switching phase can be control in reverse order also, so it is interesting point to me, it not shock end device so much, but nothing to conclude how circuit look...
For control mains transformer primarry windings, is it better (efficient) to triac act normally or in reverse order?

[stj]

i dont think you can use a simple diac+triac circuit for 0-100% because you need a minimum threshhold to drive it all
i think the lower limit is about 5%

[sam_sam_sam]

Plus the fact that I do not think that you can have it all either you do leading edge or trailing edge but do not think you can use the both edges at the same time so if that is the case then you have to decide what uses the most of the sign wave and the most efficient use of it

Now to me is how smooth the transition from fully off to fully on the question is how attainable is this process and how difficult is going be built it and what are trade offs going to be this is the question and the question also is can this be done with a transformer being controlled this is what I am interested in and have been for a very long period of time and I have not really found the perfect solution to this question and issue with controlling a transformer

This is I have been following this post now I have found a few solutions but you are giving something up the either the transition is not very smooth or you do not get fully off or fully on or it suddenly turns on and it is not very smooth transition and suddenly fully on it is usable but I more interested in something that is smooth transition for the majority of the transition if I have give up fully off and fully on because if I going to use it for battery stud welder this is the consideration that has to be considered for best results

This is also has to be be reliable and repeatable and consistent each time to achieve this is the hardest part of this process

[sam_sam_sam]

i dont think you can use a simple diac+triac circuit for 0-100% because you need a minimum threshhold to drive it all
i think the lower limit is about 5%

For my application would be fine but the question is what would be the closest fully on is the question now if it is 90 to 95% for fully on great but how is transition from first turning on to almost fully on

[stj]

it can be done with a microcontroller monitoring the zero-point but who needs such precision?

[sam_sam_sam]

it can be done with a microcontroller monitoring the zero-point but who needs such precision?

Because if you use a battery stud welder transformer it not the same as a microwave oven transformer because if use a microwave transformer you can use it with out a transformer controller but if you try this method with a battery stud welder transformer you will trip a 20 amp breaker even a 30 amp breaker I once tried a 50 amp breaker and it tripped that one as well and I had not tried to weld the the tabbing yet

[stj]

you need a slower breaker to ignore the inrush current.
that was the problem with the old 1st gen welders - a friend had one.
the inrush is almost 3 digits so upping the breaker current doesnt help - you have to use a slower one.
they sell them for industry for places with big electric motors like metal shops.

[harp]

I think I have found what I am looking...
What is transil?

EDIT
Ok, TVS diode...

[redwire]

This app note is good for what you are trying to do. More can be found in figure AN1003.12 or Teccor App note AN1003

My notes and schematic for eBay/Ali 4,000W power controller after it died - TWICE. Cheap triac, then the pot smoked. It's a good start for a simple circuit.
The hard part is getting good adjustment range, say 50% with the pot at 50% rotation.

[harp]

Nice, this is from 5% to 95%

[sam_sam_sam]

This app note is good for what you are trying to do. More can be found in figure AN1003.12 or Teccor App note AN1003

Thank you for sharing this information

[stj]

i dont think a power controller will help a welder,
you need that current-spike for the welds.