[SOLVED] TRIAC (220V 50Hz) With ATMega16 Problem [W/ Picture] Proteus

hello,
i'm sorry if i post this on wrong section

okay, here's my question, i have a problem with firing angle when i'm using 220V/50Hz AC Source...

this is my triac schematic (snubber included) :
**broken link removed**

let me show u all my virtual oscilloscope result (proteus)

Legend :
Red Pulse : Zero Crossing
Yellow Pulse : Pulse From ATMega16 Pin
Blue Pulse : Output AC

here's the pulse on 110V/50Hz with R2 470 Ohm :
**broken link removed**

here's the pulse on 110V/50Hz with R2 1k Ohm :
**broken link removed**

here's the pulse on 220V/50Hz with R2 470 Ohm :
**broken link removed**

here's the pulse on 220V/50Hz with R2 1k Ohm :
**broken link removed**

i don't know what to do, please help, any help will be appreciated, thanks a lot before
and sorry if my english is really bad -_-

Hello,

what is the role of R3? According to datasheet there is no circuit like this. Please check https://media.digikey.com/pdf/Data Sheets/Fairchild PDFs/MOC3051M_52M.pdf page 7. What is the load driven by this circuit ? Pure resistance?

Best regards

It is also important to check if current sourced to opto-diode is also properly calculated.

What is the measured current at microcontroller PB4 output pin on simulation ?


+++

R3 is about to meaningless for the shown result. R2 of 470 ohm is however still unsuitably high related to the maximum Q8025 trigger current of 50 mA.

The main problem of your simulation is that it's apparently missing a realistic load resistance. In so far the results are more or less meaningless.

sieger said:

Hello,

what is the role of R3? According to datasheet there is no circuit like this. Please check https://media.digikey.com/pdf/Data Sheets/Fairchild PDFs/MOC3051M_52M.pdf page 7. What is the load driven by this circuit ? Pure resistance?

Best regards

Click to expand...

first, thanks for ur respond, i read that datasheet u gave me, and now i'm changing my proteus schematic, i'll tell u later about how it goes...
about the load [real load, not the virtual one] is 9 watt led lamp, and sorry if i get u wrong, bcause i'm very new in electronics

andre_teprom said:

It is also important to check if current sourced to opto-diode is also properly calculated.
What is the measured current at microcontroller PB4 output pin on simulation ?
+++

Click to expand...

i'm sorry, can u tell me how to measure it? i'm using ATMega16 with 5 volt DC as source...
thanks to ur respond
i really appreciate it

FvM said:

R3 is about to meaningless for the shown result. R2 of 470 ohm is however still unsuitably high related to the maximum Q8025 trigger current of 50 mA.

The main problem of your simulation is that it's apparently missing a realistic load resistance. In so far the results are more or less meaningless.

Click to expand...

okay, i removed that R3, and i still got the same result, hmm, about the load resistance, i'm about to use 9 watt led lamp as load...
and thanks to ur respond
i really appreciate it

ATMega16 allows sink up to 20mA at pin output, but maximum operational current recommended for MOC3052 is 10mA. Perhaps a small 100R resistor on microcontroller output could be a good practice.

Surely that´s not the reason for failing, but can affect opto-coupler life cicle.




+++

i'm about to use 9 watt led lamp as load...

Click to expand...

Start with usual resistive load, e.g. 60 W lamp. The load should allow at least the maximum specified trigger and hold current to flow. Otherwise the circuit has serious problems.

I should add, that I don't know the parameters assumed for the triac model. The observed simulation behaviour is not necessarily identical to a typical real triac.

If you really intend to operate the circuit with a low power load, you should probably change to a sensitive triac.

andre_teprom said:

ATMega16 allows sink up to 20mA at pin output, but maximum operational current recommended for MOC3052 is 10mA.
Perhaps a small 100R resistor on microcontroller output could be a good parctice.

Surely that´s not the reason for failing, but can affect opto-coupler life cicle.




+++

Click to expand...

well, idk what's wrong, in virtual [proteus] when i add 180 Ohm res after PB4, the pulse won't reach the opto, but i already add 180 Ohm in the real schematic...
or is 180 is just too big, should i use 100 Ohm as u just said?

and i really can't understand this, if i use 50V & 110V as AC source, it'll be functional, but not with 220V AC, here's the pic :
schematic :
**broken link removed**

50 V :
**broken link removed**

110 V :
**broken link removed**

220 V :
**broken link removed**

and sorry, i did some experiment using moc 3052, but the one i'm about to use is moc3021
oh yes, and the triac, i'll use bta12 << is this usable for this??

FvM said:

Start with usual resistive load, e.g. 60 W lamp. The load should allow at least the maximum specified trigger and hold current to flow. Otherwise the circuit has serious problems.

I should add, that I don't know the parameters assumed for the triac model. The observed simulation behaviour is not necessarily identical to a typical real triac.

If you really intend to operate the circuit with a low power load, you should probably change to a sensitive triac.

Click to expand...

yepp, i know that, virtual is not always the same with the real thing, but, i can't get 220v working with this circuit, but it'll work with 110v or 50v...
so, i can't do [for now] what u just said [yet]...

I presume MOC3021 is not suitable to work at 220v AC.


+++

andre_teprom said:

I presume MOC3021 is not suitable to work at 220v AC.


+++

Click to expand...

well, man, i got it workeddd!!!
just now, thanks for ur all help!!

here's the working schematic :
**broken link removed**

Focusing on final real application: for sure 9W LED has some internal circuits and I'm not sure if it will be friendly for phase control.
Second thing is triac holding current. Please compare triac datasheet and load current. If you will spot any problem with operation please extend gate driving impulse to whole on-time pulse and check if it helps.
I have found quite interesting material: https://www.fairchildsemi.com/an/AN/AN-9745.pdf