Testing a Diac

SimulIDE_1.0.1-R1386_Win32

I had the idea to test the breakdown voltage of the DIACs, I have, by using the circuit of DIAC_01.sim1.

Before doing the test in real, I liked to do it using SimulIDE first to get a general idea of what I will get on the real scope.

If we run DIAC_sim1 with R1=2000 Ohm , the traces look good.

But if R1 is increased to 3000 Ohm, the traces seem disturbed, even the trace of the sinewave generator. It may not be a bug. The new value of R1 may just need re-adjusting some parameters in order for the traces to look good again.

Breakdown dinistor test

https://disk.yandex.ru/d/j15vlWiLsZ9ZRA

Yes, I have no doubt that the simulation of the diac works well in certain conditions, as the one you did for example (though I can't repeat it on my side since I have no sure idea on all parameters of the diac on your schematic).

I wonder if you had the time to test mine for R1=3K and notice the weird traces in this case (which could be seen in other conditions too).
I used 50 Hz in my example because I can vary the mains AC voltage by a variable autotransformer on my testing workbench (supplied by the secondary of an isolating 1:1 transformer).

Я вообще не понимаю, что вы собираете. Вы же просто тестируйте диаки. Что за параметры на ОУ?
Диаки применяют в основном в схемах диммеров на симисторах. Они в симисторе на управляющем электроде ограничивают амплитуду включения.
Вот ваша схема :

Вот основное применение диака DB3.


Схема диммера. Регулирует мощность сетевых ламп.

Alex68 wrote:I don't understand what you're collecting at all. You just test the diacs. What are the parameters on the OP?
Diacs are used mainly in dimmer schemes on triacs. They in the triac on the control electrode limit the amplitude of the inclusion.

I agree totally with you.
After all, the diac-triac dimmers were among my first products (we still sell them, once a while, even in these days).

And, if I understood you well, it is better to ignore what may happen to the traces in case the circuit is not supposed being practical. I also agree with you on this.

Добрый День,KerimF !
В нашей программе модель диака хорошо сделана


. Нужно просто точно указывать параметры на данный тип. Тогда он будет правильно моделироваться. Вот такие регуляторы освещения комнат у меня стоят в квартире. Вместо выключателей освещения. 230V 550W

But if R1 is increased to 3000 Ohm, the traces seem disturbed, even the trace of the sinewave generator. It may not be a bug. The new value of R1 may just need re-adjusting some parameters in order for the traces to look good again.

Yes, there is a problem simulating Diac, I will have a look.
You can see that the simulation is not working ok:



You can make the circuit a bit more stable by adding an small capacitor before the Diac (like the 100 nF used by Alex68).
But there is an unstable point related to these parameters:
Breakdown V = 30 v
Hold Current = 0.01 A
Resistance = 3000 Ohm


@Alex68:
KerimF is using the Operational Amplifier with gain=1 to plot the voltage across R1, it is not really part of the circuit.

arcachofo wrote:You can make the circuit a bit more stable by adding an small capacitor before the Diac (like the 100 nF used by Alex68).

I guess, it is normal that, in case of an unstable condition (or unreal circuit), the simulator just stops and pops up a certain warning. This helps the user, after reading this warning, to find out what he did wrong (or unrealistic) on his schematic

But, you may have another opinion.

I guess, it is normal that, in case of an unstable condition (or unreal circuit), the simulator just stops and pops up a certain warning. This helps the user, after reading this warning, to find out what he did wrong (or unrealistic) on his schematic

The warning is there.
The simulation doesn't know if it is an unstable condition or what.
But the warning is telling you that it might be a problem with some non linear component.

arcachofo wrote:

I guess, it is normal that, in case of an unstable condition (or unreal circuit), the simulator just stops and pops up a certain warning. This helps the user, after reading this warning, to find out what he did wrong (or unrealistic) on his schematic

The warning is there.
The simulation doesn't know if it is an unstable condition or what.
But the warning is telling you that it might be a problem with some non linear component.

Okay, I will keep an eye, during a simulation, on the warning corner with the hope it will last for a few seconds; enough time for one to notice the warning and stop the simulator (to avoid getting weird results).

@Alex
I couldn't find out how to translate words on an image.
I used to translate a datasheet if offered as PDF.

KerimF wrote:@Alex
I couldn't find out how to translate words on an image.
I used to translate a datasheet if offered as PDF.

Есть вот такая утилита. Обводишь пером тест на картинке и переносишь в переводчик !

Alex68 wrote:

KerimF wrote:@Alex
I couldn't find out how to translate words on an image.
I used to translate a datasheet if offered as PDF.

There is such a utility. You circle the test on the picture with a pen and transfer it to the translator!

Thank you, Alex.

Unfortunately, it seems that ABBYY for screenshot is not offered for free.
Since the start of the Arab Spring, it became not easy at all, from where I live, to transfer, by an independent citizen as I am, any amount of money out of the country

This luxury was possible in the past golden years only... before the people, among whom I was born and live, have been saved, since March 2011 till now, by the world's Elite  

Держите. Совершенно бесплатно.

https://disk.yandex.ru/d/jyvankrqxyBCPw

Alex68 wrote:Here you go. Completely free. https://disk.yandex.ru/d/jyvankrqxyBCPw

Thank you.