See this circuit... You can connect your 40w bulb instead of motor in this circuit... Hope it ll usefull to you...
Sorry... It is good to use an optoisolator (with triac as ouptut) but in this circuit from where the gate of the main triac can get its driving current?
Kerim
Edited:
I mean let us make a short on the output of the optoisolator... what could happen? Nothing I guess :wink:
---------- Post added at 19:55 ---------- Previous post was at 19:43 ----------
Hi. Would it be possible to use **broken link removed** (or any other suggestions) TRIAC to switch 40W bulbs connected to a 240V power supply using a 5v signal? (Arduino Microcontroller)
I am unaware of exactly how triacs function and know only that i want to simply be able to control my bulbs using my computer. I have tried relays but they are noisy and suffer from that irritating EMF kickback. ANy help would be very much appreciated.
Danny.
The main advantage of relay is its electrical isolation. So your PC is safe when using it.
About triacs, a good circuit using an optoisolator is already posted. Unfortunately it has now a minor mistake (in one connection)... I believe soon it will be corrected and your problem be solved... the driving circuit is also explained in the datasheets of the MOC series.
Kerim
Edited:
6-Pin DIP Zero-Cross Optoisolators Triac Driver Output
MOC3041M, MOC3042M or MOC3043M
They differ only in their input sensitivity (15, 10 and 5mA)
All these 3 ICs are made for 400V peak (good for 220Vac)
Correcting the error on the posted schematic:
The resistor which is between the opto output and the A1 (lower terminal of the main triac) should be connected instead to A2 (upper terminal of the triac). The value of this resistor (which limits the current in the opto triac output) could be 390 ohms.
In case of small triacs (<10A), it is also better to add a resistor (say 330 ohms) between the triac gate and A1 (equivalent to cathode for thyristors).