BMS Doug wrote:
i am an middle and high voltage electrician and 220 V circuit is not a problem, i will do it right.
I tought that there is a problem within an relay.
Thanx to davidcoton, i thought so, is not a simple way to do two-way circuit. I will look for some other solution.
given that you claim to be an electrician then I would suggest that you use the relay (many SPDT versions are available) and a light switch to make a standard two way lighting circuit.
If you need further hints about using a relay to operate as a light switch then you aren't really an electrician.
Make certain that the relay board that you have is actually safe for use with the voltage as cheap imports may not have safe isolation distances on the board. Also ensure that the relay board PCB tracks are protected from contact by some form of enclosure.
You're right, I went to the Electrical Engineering High School 18 years ago (4 years, with my 15, 16, 17 and 18 years old, now I have 35 years old). Then Maritime Studies, 2,5 years of marine electronics ... Now, more exactly last 10 years I'am Oracle, Clarion and PHP programmer, so that a lot of the basis of Electrical I have forgotten but good part is still here, just need to remember some stuff because I have never worked as an electrician, so, my working practice as electrician is equal to zero...
But, i am not sufficiently well formulated question.... I have GPIO 3,3 V signal from raspberry pi that triggers relay on relay board with an opto isolator and want to connect this relay board with an ordinary switch in combination to switch light on or off from low and middle voltage, something like cross-switch, with switch on wall or my smartphone!