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Phase control Shaded pole motor

Vindhyachal Takniki

Apr 29, 2015
9
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Apr 29, 2015
Messages
9
1. I have to control the speed of shaded pole motor. For this i have selected phase control method using TRIAC.
I have a connected a 10K pot at adc input of MCU, as pot is rotated MCU sense the reading & accordingly control the phase. (voltage = 220vac)

2. Now if I connect a 100W bulb at the output & then rotate the pot, I am successfully able to control the intensity of bulb like in gradually goes dimmer or brighter.
Also I have connected a ac voltmeter at load, I can see gradual increase/decrease in voltage of bulb as phase control is done.

3. Problem arises when I connect motor. Attach is the ckt diagram showing snubber circuit & triac connections. Ckt again don't work.

4. I had bought a low cost ceiling fan regulator & strangely it works. I had checked its circuit, the additional feature is it has diac to control firing angle rather than MCU pin for controlling it via opto-triac.
They are using 4q triacs

5. I think my snubber circuit values are wrong?
 

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  • snubber.pdf
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ramussons

Jun 10, 2014
462
Joined
Jun 10, 2014
Messages
462
Replace R2 with 270 ohms and connect it to the anode of the triac instead of from the snubber.

images
 

ramussons

Jun 10, 2014
462
Joined
Jun 10, 2014
Messages
462
No, it does'nt require 2 snubbers. The point I'm making is the pin 4 of MOC3021 is to be connected to the "anode" of the triac, not to the snubber.
 
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