Hi all,

Short explanation:

I give 5v to [power control] --> AC Device ON
I give 0v to [power control] --> AC Device OFF

please advice simplest & cheapest option for [power control]

P.S>I will not use relays


Long Explanation:

Basically I want to switch the AC (230V 50Hz) powered device on/off as per the MCU signals (Programmed logic )

for signalling I have 5v from normal I/O pins

I have considered Mechanical relays but I don't think they could run on the low current from the I/O pins .. further more I do not want to add a motor driver to control the relay as it will make the design more complicated and much of the power will go for keeping the relays engaged!

So,I am looking for an electronic device/circuit for the purpose such as a MOSFET or something called as TRIAC

But, I am pretty dumb at electronics

can someone recommend a decet way to control the AC power to device using just the 5 v

 

Nothing says you can't drive the relay with a transistor or MOSFET.

There are a number ways to do this.

Solid state, relays, optocoupulers etc.

 

So,I am looking for an electronic device/circuit for the purpose such as a MOSFET or something called as TRIAC

Look at this:

http://www.fairchildsemi.com/ds/MO/MOC3042M.pdf
The MOC3043 only requires 5ma drive current, drives a suitable Triac very simply.

 

The trouble with triacs is that they inherently involve connecting your low-voltage electronics to the high-voltage line. This really is something to avoid in anything you build yourself, and I believe talking about it violates the terms of service for this board.

The opto-isolator component is usable, though it still puts the high and low voltages very close together. And that little device isn't good for much current.

I think you should use a solid-state relay. Much closer to foolproof, can handle plenty of current, can be driven by a microprocessor output pin, don't cost much.

Pictures of several types here:
http://en.wikipedia.org/wiki/Solid-state_relay

Note that "trouble with triacs" is not the same as "trouble with tribbles".

 

The trouble with triacs is that they inherently involve connecting your low-voltage electronics to the high-voltage line. This really is something to avoid in anything you build yourself, and I believe talking about it violates the terms of service for this board.

Thanks for reminding me .

Just don't feed them.
I'm heading to the shop now to work on my rudimentary lathe.

 

You could just get one of these:

http://www.ebay.com/itm/Solid-State...178?pt=LH_DefaultDomain_0&hash=item1c1f15f5da

http://www.ebay.com/itm/Solid-State...357?pt=LH_DefaultDomain_0&hash=item19c83b3b1d

I've got some here but never checked them out, I click BUY on the AC units when I wanted the DC ones. I did note the DC had a fairly high (and constant) sat voltage.

They do claim full input-output isolation.

Digikey also has these, but at much higher prices.