I'm a programming student and I got into an Arduino class this semester. Here's some backstory behind this question:
I need to make a Bluetooth module switch modes from master to slave and back, but I found out that the module only switches modes by being unpowered then powered again (and doing some specific things). This means I would have to unpower it manually by unplugging its power, but that'd mean it wouldn't be completely automated, so it's a no-no.
Because of that, I'm considering using a relay to be able to power it down then back on again via code, and found some relays that can be controlled by supplying 3.3-5 V.
However, all relays I've seen state that they work on 30/110/220 V.
So, if I use 3.3/5 V to control the relay, and 5 V to power the module through the relay, will the circuit through the relay work?
Best Answer
This could work. The voltage requirement you must meet is for the coil. The contacts are rated for the maximum voltage they can safely interrupt. You will start to run into problems with the contacts with very small voltages, but 3.3V is high enough for the vast majority of relays out there to not have a problem.