how to make a digital relay (solid state?)

Hi, sorry if this is already covered, but i am not even sure of the proper name :smiley:
I want to send an external signal or current to either two outputs, like a relay, but i need it to be small, and not power hungry like a proper relay, i really don't know how to make it or if there is an ic that does that!

It should have an input, an N/C and an N/O just like a relay to act like a 3 pin jumper/deviator but controlled in software.

Does it make sense?


There is lots of IC's that can do that, but not with high current or high voltage.

Try google with "analog switch ic"

// Per.

Yes, google has plenty of examples. If the amperage is greater, then google solid state relay. You can see typical circuits or buy a finished product. Considering that you are working with AC mains, buying a finish product isn't a bad idea if you are a newbie. A solid state relay typically only needs 5-10mA, at any voltage between 4 and 32 VDC.

Nothing solid state acts exactly like a mechanical relay. Almost all solid state relays start with an opto-isolator, but AC & DC solid state relays use different components and they work differently.

I've made AC SSRs with TRIAC and a special opto-isolator that's made for driving a TRIAC. These can be used for regular on/off control, or for phase-control light dimming if you sync to the AC line frequency. It's not too complicated (unless you are dimming), but it's easy to fry things (or shock yourself) when playing around with AC power.

Ok now that i know the general term i can google it :smiley:
I don't need it for great currents, my idea was to build an sip shield for both atmega328 and attiny, since they have different pinouts i would like to be able to reconfigure the socket via software, i know that it is simpler to wire two distinct sockets together, but this is more of a concept to try, just for fun...

A more useful project would be this.
I have various arduino clones that have different serial pinout, now i have made an adapter from the original arduino usb2serial to luigino and to seeduino sensornode (2 nodes 2 different wirings, doh!) and it also has 5v and 3.3v switch, another idea would be to make a "universal" usb 2 serial with various configuration options, for every board, and 2 voltages, that you can choose on the fly with some switch, reading on an lcd the applied configuration

in this case only the 5v and ground would be probably high current, if 100-300ma can be considered that.