Hello All,
I need help. I am developing home automation. I have tried to use the TRIAC BT136 and BT139.
While I am using TRIAC I got 100millisecond spikes when I switch on the nearest loads in my home.
The CFL Bulb is suddenly on and off when i switch on the nearest loads in my home.
(example: my Hardware and arduino live that time I switch on my nearest loads uisng my wall switch manually Suddenly I got small spike on my CFL) suddenly CFL Blink once.
I have connected TRIAC with CFL bulb. triac is operated by arduino using MOC3041.
I tried many circuit possibilities But I cant
I tried snubber RC.
0.1uf and 2w 100 ohm resistor. no improvement.
please help.
And Can I use MOC3041 Optocoupler directly to switch on the loads ?.
I checked this also with cfl bulb MOC3041 once switched on and does not off.
Any one give me idea to solve this problem.
I have attached the circuits withis post please find. this is I got from internet
Have you tried fitting a mains rated Contact Suppressor across the switch / device causing the problem ?
Have you considered using ready made Solid State Relays, the smaller 2, 3 or 4 Amp modules can be as cheap as building your own, and a lot safer.
However they can still 'blink' like your component builds if you have switching noise on the power lines.
Thanks for Reply.
ricky101:
Have you tried fitting a mains rated Contact Suppressor across the switch / device causing the problem ?
Contact Suppressor ? means ?.
Have you considered using ready made Solid State Relays, the smaller 2, 3 or 4 Amp modules can be as cheap as building your own, and a lot safer.
However they can still 'blink' like your component builds if you have switching noise on the power lines.
Can I use MOC3041 for driving loads(without Triac)
Solid state relay is reliable ?.
You can't use a MOC3041 to drive any significant load.
How are you driving the it's photodiode?
regards
Allan
Have to say that playing around with mains voltages and Triacs without the required knowledge can be very dangerous and not something I would recommend.
If in doubt, consult a qualified electrician.
Can you use a MOC3041 ? - the first thing you should look at its its Datasheet which tell you its maxium output load. as you can see its only intended for very small loads.
http://kubuntu.free.fr/wiki/data/fp/moc3041.pdf
This link shgows an example of a mains voltage Contact Suppressor.
http://www.maplin.co.uk/p/rc-contact-suppressor-rg22y
One of the most important things about it, and any capacitor you need you use on the mains side of any Triac circuit is that they should be Class X or Class Y types.
Do you know about them ?? if not you need to find out otherwise you can get devices exploding !
Ok. Thanks
I used that type of capacitor. but Still I get the spikes.
is solid state relays are reliable ?.
Yes, SSRs are reliable if used correctly.
However they do not fully isolate the circuit as a double pole relay would.
The capacitors on the triac are to prevent interference etc from the triac.
You need to try and remove the souce of the interference by using a suppressor on the circuit/switch creating the interference.
There may be other ways to overcome that problem , others may be able to here you there ...?
Hi,
The opto couplers you are using are not zero-crossing switching type.
If all you are doing is switching ON or OFF a load, (not PWM) you should be using a zero-crossing opto-coupler.
They switch the Triac ON at zero voltage crossing point, thus producing very little switching spikes.
So look up zero-crossing OptoIsolator from your supplier.
Tom.... 
It;s normal to use a significant inductor - 100uH? in series with a big triac to reduce the large dI/dT transients which cause interference..
Look inside any commercial light dimmer switch
regards
Allan
Need to add an inductor ? in series with load.
Connect a 10K resistor between MOC 3041 pin 1 & 2; this may solve the problem.
Ok. I am try this one also
allanhurst:
Re your #9,,,,
yes
regards
Allan
What Kind of Inductor need to use. And details. Henry ?.
Air wound inductors ? toroidal core ?.
Send me the link.
This is for home appliances control
Home automation project. So usually I am going to control the CFL, TV, FAN, BULB, PC, AC, WASHING MACHINES, etc...
So what kind of TRIAC I need to choose ?.
Please send me the links about that part details...
I'd suggest about 100uH. Toroids are commonly used. And ( like everything else ) have to be rated to take the maximum current you'll be switching ie rms x 1.5.
The only worry I have in your above list is the washing machine -which coulkd take at least 2kW.
Have you considered using solid state relays (SSR's) - which do exactly what you want and save a lot of experimentation -driving high power ac loads is a bit more complex than you think, and could end in a lot of fried components unless you know exactly what you're doing - and reading your entries makes me think you don't.
They're not very expensive.
regards
Allan
Ok. Thank you. I going to try this SSR
