I would like to control AC devices with a microcontroller. I found this nice tutorial on how to build a relay based controller. It would work great, but I was wondering, can I replace the relay with something non-mechanical such as a transistor or maybe a solid state relay?

Can a transistor be used in such an application and if so, what is the model number of one that could handle 120V and the current of, say, a 60W incandescent bulb, a hair dryer, etc?

 

use a mechanical relay or solid state.
There are numerous "relay shields" for the arduino that a simple digital pin drives an optocoupler which drives the relay.
mdfly 4 channel relay shield is one I've used before. It works perfect.

That sparkfun single relay board is just fine too. It uses a transistor to drive the relay.

 

Get a solid-state relay, something like this:

http://www.digikey.com/product-detail/en/S108T01F/425-2395-5-ND/720455

or this:

http://www.digikey.com/product-detail/en/CX241R/CC1601-ND/751952

There are literally thousands from which to choose.

 

Problem is I might want to switch rapidly. Need something fast.

 

You will need to have a better definition of "fast". Are you talking micorseconds, milliseconds or seconds.

 

Let's say light bulbs switched on/off to music.

 

or this:

http://www.digikey.com/product-detai...1601-ND/751952

In the datasheet for this one, pin 1 is Load A and pin 2 is Load B. How does it all work exactly? I switch it on through pin 3 and 4 with the microcontroller, but how do I connect the GFCI in the tutorial using pins 1 and 2?

So I would connect a

 

Let's say light bulbs switched on/off to music.

Thats not fast in the electronic world.

 

Thats not fast in the electronic world.

point taken

 

Use Google and look up "Color Light Organ" to see a lot of possibilities.

My advice would be to be sure to use an isolation transformer on your incoming power.

Near the bottom of this page, you may see something you could use......

http://www.loneoceans.com/labs/arduinolights/

Google found it!

 

Use Google and look up "Color Light Organ" to see a lot of possibilities.

I know about color organs, but I want to do something simple with wall AC. Switch a lamp on/off, a hair dryer, etc.

 

So you are going to play music through your hair dryer???

 

Sweet! Thanks!

 

If you get a SSR, it should do anything you want. BTY, where did the music come in?

 

In the datasheet for this one, pin 1 is Load A and pin 2 is Load B. How does it all work exactly? I switch it on through pin 3 and 4 with the microcontroller, but how do I connect the GFCI in the tutorial using pins 1 and 2?

So I would connect a

Pins 1 and 2 would act like the two contacts on a normally open switch. With no signal on 3 and 4, it would be an open. Put the proper signal on 3 and 4 and 1 and 2 would conduct AC current. What tutorial???

 

BTY, where did the music come in?

What do you mean?

 

Let's say light bulbs switched on/off to music.

There.....

 

Pins 1 and 2 would act like the two contacts on a normally open switch. With no signal on 3 and 4, it would be an open. Put the proper signal on 3 and 4 and 1 and 2 would conduct AC current. What tutorial???

Here's the tutorial (it's in my original post): http://www.sparkfun.com/tutorials/119

As you can see in it, the black wire is switched. But how do you switch both AC wires? I know it's basic. Just have fun with it

 

There.....

I was just saying that I'm not quite sure what I'm going to do with it. I just want to have an outlet controlled by an arduino. For any home appliance basically. Light bulbs included

 

Since you don't post where in the world you live, I can't really give any further advice. If you live in the US, only the HOT wire would be switched and the neutral would stay connected to the input of the GFI. You will be switching the HOT section of the GFI ON/Off instead of switching a light ON/OFF.

Don't get hung up on the Solid State Relay vs a regualr coil/contact relay. Even though the insides are different, to the outside world, they are the same.