Im using a relay paired with arduino for a appliance detection project. Currently I'm facing the issue that I want to know out of which 4sockets connected with the relayy the appliance in plugged in with. I want to know out of the 4 outlets which one did the consumer plug the appliance into. Some help regarding this? I'm clueless guys!
OK, so you have a power source with 4 possible current consuming devices. You want to know which of 4 sockets has current flow including more than one at any given time. I also assume AC current 50/60 Hz. Since voltage is always present voltage detection is out but any load will draw current so current detection (current sensors) would likely work. All you care about is if there is or is not current flow. You are not interested in how much current, just if it is there or not.
A simple quick home brew approach would be go to your local home improvement store (or similar) and buy some magnetic reed switches. Make a coil (you will need to try different turn counts) and wrap it around the glass envelop of the reed switch. Current flow in the coil will create a field and close the switch. The switch will open and close based on mains frequency.
Another option is turn key, store bought is using some of these:
Those or similar and if current detection of low currents is an issue you loop the primary (line wire) through the donuts multiple times.
Beyond that you can look to AC Current Sensors and a Google of " ac current sensor arduino" should bring up plenty of hits and suggestions. Just a matter of how you choose to do things.
Ron