I want to use an arduino to make my light switches respond to my TV remote. I understand an ordinary mosfet or power transistor probably wont be up for the task. I do have on hand two BTA41-600BRG triacs rated for 600 volts and 40 amps. Would these be the right components for the job? How do Triacs compare to transistors or mosfets?
A safe/easy way is to buy a 3-pack of remote controlled power switches.
Something like this:
An Arduino with a remote control receiver and a 433Mhz transmitter can translate the remote signal and switch the lights on/off.
Leo..
If you don't know the difference between transistors, mosfets and triacs, you probably should not be playing around with the 110 (0r 220 for those on the other side of the pond). To do it safely requires care and isolation from the mains. You can get seriously hurt with the 110 (and it doesn't do the end of the screwdriver any good either when you burn it off!!). Not being nasty here, it is just a safety issue working with those voltages.
Another safe way:
Leo..
Thanks for the safety tips. I have touched 350v capacitors and 110v mains before and needless to say, I would like to avoid another shock. I think I'll go for those safer pre-made options, even though it wouldn't be as fun. I understand the difference between a transistor and a mosfet and I'm pretty sure I understand the applications of triacs, but I have no experience with them. I'll gain some experience working with low voltage AC circuits first.
Using an opto-isolated relay is also a safer alternative - especially for your poor, sensitive Arduino. You, on the other hand, could still get zapped.
But take at look at my video #18 (URL in my signature) that describes a relay that would work. It shows a dual relay but you can get them in multiples of 1, 2, 4, 8, 16... and at a great price from the Far East too. I'm sure eBay will be your best friend to at least get an idea.
Setup and my test results. Now it runs for few years wirh zero failures. See the tuxedo cat
... And be careful
Both bipolar and MOSFET transistors act somewhat similar in that a change on the gate/base results in a change of current through the transistor (bipolar transistors respond to base current while a MOSFET responds to gate voltage). Triacs and SCR's (a triac is basically a bidirectional SCR) turn on with an input to the gate and stay latched as long as there is current through them. They then turn off when the current goes to 0 - a triac can handle current going either way (which is why they are the normal component of a light dimmer - they adjust the turn on time in the cycle and it turns off at the zero crossing point). SCR's are the same, but only with current going in one direction - they don't work in the negative half cycle. Over simplified, but a basic idea - transistors can be used in the linear mode (or driven into saturation), SCR's and TRIACS only operate as latching switches.