I know that there are plenty of questions related to relays, but I have to ask. I am trying to sort out the issue and spend hours reading but cannot make progress.
I have SainSmart 2-Channel 12V Relay Module for Arduino and wired it according to picture.
Arduino UNO R3 board is powered from 12V plug external power supply. I take that 12V to power JD-VCC on relay (from VIN). Arduino 5V is used to power optocoupler circuitry.
I want to use to power 12/24/220V devices (on picture I wired 6V battery for troubleshooting).
So, when I set PIN7 to LOW i would expect that fan spins up. LED on relay goes RED, so I expect it is sign that relay is activated. However, fan does not power on. When I bring PIN7 to HIGH, I hear click; LED goes OFF. I assume it deactivated relay. All the time I have 6V on voltmeter.
What I am doing wrong? I really tried to find answer around, but either I do not see or it is not so obvious.