I am looking for some solid state relays for my develop. I am using an arduino fio so I think it should be swithed at 3v.
I know ssr are more expensive than mechanicals but all websites I check they are x6 or more times... If I just needed one, I just buy it but I need about 7 or 8...
I want that my develop keep working for 3 years or more and almost sure it has to change the state of the relay every 20 seconds.
My requeriments for the relays are: 220v AC, 2A. switched by Arduino fio 3vDC
That is unbelievable cheap, so it is probably very simple.
But if you load is only lamps, you can try it. And inductive load like a motor requires a good electric noise suppression.
If it doesn't get hot, it will probably keep working.
If you want to be sure, buy a few and open one to see what is inside.
I bought a couple of these, they're just sitting on the floor bagged up still until my thermocoupler arrives but these feel very solid and well built for the price ......
I was only talking about the SSR (Solid State Relay).
...so the SSR is probably very simple...
... you can try the SSR...
... If the SSR doesn't get hot ...
... buy a few SSRs and open one ...
I have one of those larger SSRs, a SSR-25DA. They are also very cheap, but they seem okay. They have a large noise suppression, a small lamps could glow very dim if the SSR-25DA is switched off.
Those relays seem too big for me. They are bigger than arduino fio I think I will order a couple of simple ones I posted and check if they work fine or not. When I receive them, I will open one of them and post photos here.
There has to be some kind of mosfet capable of handling > 240volts and maybe an Optocoupler?
I'd love to see images, unless i go outside and started bashing the relay against the concrete, I have no other tools to open one up with and find out for myself so please do remember to take pictures
I don't know what's inside one but I imagine it's just a few diodes and MOSFETS.
Mosfets? No, that's unlikely.
SSR's are for AC loads and though therefore have an AC component like a TRIAC (which is a bi-directional Thyristor/SCR). It would also have an opto-coupler and some snubbing passive components along with (in the good ones) some zero-crossing based gate control.
Making your own would likely cost more than buying a ready made one... but people do it. IE, Buy MOC3010 (or MOC3024) for opto-coupler, a ON SEMI Part # T2800DG and find some sample Triac/SSR circuits... like...
but these feel very solid and well built for the price ......
I think I will order a couple of simple ones I posted and check if they work fine or not. When I receive them, I will open one of them and post photos here.
so please do 
