About chip number and operation that is used in dimmer triac

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SINDHURI

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Good Morning one and all,

I want to know what is the chip number and operation of the chip that is used at the bottom of the module to control the intensity of the bulb or fan that is designed by sunrom technologies.

Link for the Data sheet:
Datasheet: **broken link removed**

Please reply me as early as possible.

Thanks in advance.
 

i know the owner of sunrom, as i am from ahmedabad, his office is near to my place. all i know is that he used to make such devices using pic microcontrollers, for the ic you are asking about, should be pic12 series microcontroller. (he has told in the datasheet that it is a microcontroller.)
and as the code provided in the datasheet. i can tell he is using PWM to control the brightness. from the data0,1,2,3 he is setting brightness to for levels. 25 50 75 and 100%.
if you know the coding of microcontrollers, you can do it easily on your own.
 

According to the pin connections on the picture, the ic SEEMS to be a PIC12 series microcontroller (I see GND goes to pin 8, +5V Vdd COULD go to pin 1 and a 10K resistor is placed between +Vdd and pin 4 that is MCLR on PIC12xxxx). I can't read the IC marking so of course it can be another microcontroller of microchip or other manifacturers.
You can find some theory of operation of such configuration on microchip site www.microchip.com, search for "dimmer" and choose the application notes results.
I see also it uses a couple of optocoupler, the 4 pin one( BLACK) is supposed to detect zero voltage crossing of main voltage, the second one (white) to drive the triac, so the tecnique for dimming is phase control, and NOT PWM (the datasheet also states this). The microcontroller, after the zero voltage crossing trigger, simply waits a certain time (0 to 10 mS, half cycle of main's synusoid), according to the 4 bit code on the input pins D0-D3, then fires the triac.
 
Last edited:


i already using this moc3021. it is used to drive triac. 3 leg ic is triac. 8 pin ic is surely pic12, as i have told before.

by the way what do you mean by zero vlotage switching type.???
 

FvM said:
MOC3021 isn't zero voltage switching (MOC3040 e.g. is), otherwise it won't work for a dimmer.

By the way, I wonder if electronic design in India doesn't care for safety rules, as previously mentioned. https://www.edaboard.com/threads/285664/
Click to expand...

i have seen sunrom's office, and it looks like a hooby center more, than a company.

- - - Updated - - -

ok my mistake. it is not pwm. its phase control mathod. device should be using that black opto for this function.
 
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    FvM

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Good Evening Sir,
Sir, Please can you tell me the preferred number of this PIC12 series Microcontroller.

Sir, as you told that the MOC3021(white) is to drive the triac, then what is the necessary of using this Microcontroller chip at the bottom of the Module.

Please Reply me as early as possible.

Thanks in Advance.
 

moc is basically an optocopler, it does not have logic to drive triac. you have to read posts about phase controls methods, and implement its logic on a micro controller. and low cost micro can be used.
if you want to use pic than u can search for one here...
https://www.microchip.com/maps/microcontroller.aspx
 
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    FvM

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The microcontroller controls the triac. There is an optocoupler between the microcontroller and the triac to isolate the low voltage circuitry from the high voltage circuitry.
 
ec_nisarg said:
i already using this moc3021. it is used to drive triac. 3 leg ic is triac. 8 pin ic is surely pic12, as i have told before.

by the way what do you mean by zero vlotage switching type.???
Click to expand...

Hi

Maybe you have noticed I edited my previous message about MOC3021 after the first write.
I was wrong about it is a zero voltage switching type: it isn't. And it can't be, otherwise it can't does phase dimming!
Such kind of optocoupler is better called "zero crossing" (see for example MOC3031 type, that was the one I mix up with 3021) because they drive ON their output only at the zero crossing [of main voltage sinusoid] time to avoid switching noise and current inrush. Internal additional circuitry allows this behaviour.
But if you want do phase dimming you must be able to switch on the triac in any point (angle) of the sinusoid, so you have to use classic plain optocouplers like MOC302x types.
 
also i was not aware of firing angle. i googled it, so at last we are agreed that this circuit uses, 4 pin opto for zero detection and moc for gating. by the way thank you for making me learn this theory.

we are using moc to fire triac. but we simply switch on or off, not dimming it.
so i was not aware about it.
 


Good Evening Sir,

Please reply me the preferred number of the PIC12 Series Microcontroller that is used in the module. I want to know the chip number that is presented in the datasheet.

DATASHEET LINK:

**broken link removed**

Thanks in Advance.
 

SINDHURI said:
Good Evening Sir,

Please reply me the preferred number of the PIC12 Series Microcontroller that is used in the module. I want to know the chip number that is presented in the datasheet.

DATASHEET LINK:

**broken link removed**

Thanks in Advance.
Click to expand...

only the owner of the sunrom knows which ic it is..., and he wont tell you either, i know him, he used to erase numbers from ics on his products, so one can not copy it.

by the way you can use any low cost microcontroller for this application.
one more question from my side. do you know programming of pic microcontrollers.??? pardon me if this is rude...
 

FvM said:
Even if the code is protected, you still can read the chip ID with a programmer.
Click to expand...

how it can be done???

i know that each chip has id number but i can only read it when i goes to program it.. and in mplabx only single letter of id is shown. like id:8 or id :0x3a, how to determine from that id ??
 

Does it matter what chip they used anyway? Seems to me it would be easier to come up with your own design than to reverse-engineer that one.
 

godfreyl said:
Does it matter what chip they used anyway? Seems to me it would be easier to come up with your own design than to reverse-engineer that one.
Click to expand...

yes you are right. as we have already find out that what this circuit actually does. one has to simply write small logic on micro.. any micro..
 

godfreyl said:
The microcontroller controls the triac. There is an optocoupler between the microcontroller and the triac to isolate the low voltage circuitry from the high voltage circuitry.
Click to expand...

Good Evening Sir,

As you told that Micro controller is used to control the triac. Then what is the use of MOC3021 Optocoupler in the module.

Please clarify my doubt. And also tell me the function of Moc3021 Optocoupler in this module.

Link for data sheet
**broken link removed**
 

microcontroller is a digital device... and triac works with AC voltage, so you need some kind of link between them, moc3021 is the link in this module, microcontroller can not directly control the triac, mainy for two reasons, 1. it is digital device, 2. it can not provide enough current to threshold the gate of triac.

i think you didn't understand godfreyl's comment completely, he has already stated that moc3021 isolates low voltage side from the high voltage side, (i want to add one more word here, not only high voltage side, but high voltage AC side.)
 

SINDHURI said:
tell me the function of Moc3021 Optocoupler in this module.
Click to expand...
As I said: "There is an optocoupler between the microcontroller and the triac to isolate the low voltage circuitry from the high voltage circuitry".

The triac is switching mains voltage, but the microcontroller must not be connected to mains voltage, so an optocoupler is used.

The microcontroller switches on the optocoupler and the optocoupler switches on the triac, but there is no electrical connection between the microcontroller and the triac or any other high voltage part of the circuit.

BTW, the Moc3021 is an opto-triac, not a normal optocoupler.
 

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