Hi, how to trigger a 220V device using the Arduino? I'm thinking of using a NPN Transistor to use as a switch device to turn it on but i do not have experience using it for 220V. I only tried it for 12v devices using TIP 120. So is it okay to use transistor like TIP48 or MJE13006 for this 220V device?
Caraanmjv:
Hi, how to trigger a 220V device using the Arduino? I'm thinking of using a NPN Transistor to use as a switch device to turn it on but i do not have experience using it for 220V. I only tried it for 12v devices using TIP 120. So is it okay to use transistor like TIP48 or MJE13006 for this 220V device?
You can't a transistor for AC power, it only conducts in one direction.
Use a relay.
You need to use either a mechanical relay, or a solid state relay (SSR), or (if the load current is light enough) an opto-triac.
If you want to build your own SSR, you can refer http://electroschematics.com/6267/do-it-yourself-solid-state-relay/
Hey I am currently in the final stages of my design activating two 115VAC fans using the Arduino. I am using just a simple relay. If your interested I can show you what/how it works.
Lance
Thank you for your replies. I already bought a relay with maximum of 7A 250VAC. The device is 10W so i don't really need a high ampere for that. Now it is time for testing, can i attach a 220VAC in a breadboard? i only had experienced experimenting in school low dc voltages.
Could be a shocking experience and could kill you!!
Sure, test the relay with the arduino, no mains voltage required there, once thats working
then you need to put everything into an insulated box and wire the relay to your device.
High voltage and current must be handled with care
Caraanmjv:
can i attach a 220VAC in a breadboard?
No.
Don't even think about having 220VAC wires around your workplace. The only place they should go is in the relay and the relay should be on a long wire while you're developing.
PS: What relay have you got? Make sure it has protection diodes or you can zap your Arduino with it.
https://www.google.es/search?q=relay+protection+diodes+arduino
Thank you for the warning. Thank God i posted first before trying. The relay is NAIS DSP2a - DC12V, 5A and 250VAC. It is a 6 pins relay, i'm only familiar with the 5 pins,can't find anything about the pin configuration of this. This is the datasheet, http://www.datasheetarchive.com/DSP2a-DC12V-datasheet.html#
This is the schematic diagram that i will use.
I tried the relay and the 220V AC device. It was a success. Now i will try it with the arduino and power transistor. My final question, is it okay to use one dc power supply for the 12V Relay and Arduino? My power supply is rated 1.5A.
You don't need a power transistor to drive that relay, just a small signal transistor. It only takes 25mA. Don't forget the diode across the relay coil.
You can use the same 12V power supply to power both the relay and the Arduino.
This is my schematic diagram. http://www.flickr.com/photos/knittyissaw/8203039988/in/photostream
Is that okay?
Caraanmjv:
This is my schematic diagram. schematic | Melissa | Flickr
Is that okay?
Just missing a series current limiting resistor between the arduino output pin and the base terminal of the transistor, 500 ohms should work OK. Also be sure there is a wire installed from the negative terminal of the 12vdc power supply to a arduino ground pin if the 12vdc is an external DC power supply. Be sure the transistor is rated for current well above the value drawn by the relay's coil.
Lefty
Thank you. I will use a TIP 120 Transistor. 
TIP120 is overkill by a huge margin (we've already established that the relay takes only 25mA). BC337, 2N2222 or even 2N3904 would be more appropriate. I suggest a base resistor in the range 1K to 2.2K, because 2mA base current will be more than enough.
Ahh. I didn't understand that, I think I need a transistor tutorial. As far as i know it will only increase current in the collector and emitter but the relay is connected to the collector of the transistor, so no amplification of current that will pass in the coil of the relay coming from the transistor? And the current will come only from the 12V power supply? The coil of the relay also has a built in 500 ohms resistance.
I also used this as a reference. The transistor will act as a switch and not to amplify. http://bildr.org/2011/03/high-power-control-with-arduino-and-tip120/
http://www.kpsec.freeuk.com/trancirc.htm
Scroll down the page to "Using a transistor as a switch"
Lakes:
Transistor CircuitsScroll down the page to "Using a transistor as a switch"
But it is not stated there that power transistor should not be used. hmmm.
Did some research.
It stated that for larger relays more than 5V use a TIP 102 transistor.
http://arduino.cc/forum/index.php/topic,2600.0.html
It stated here that "The TIP102 has a Vceo "collector to emitter breakdown voltage" of 100 VDC as aposed to 60 Volts for the TIP120. thats pretty much the only major difference."