I'm sure you've done this already but just checking you aren't driving the relay coil directly from a GPIO. You should be able to use a jelly bean NPN transistor like 2N2222 or PN3904 but darlington is better. If it's not darlington, use a smaller resistor. Some relays have the flyback diode integrated so you might not need that. I found this with Google image search. Substitute "GPIO" for TTL input and whatever your load is for "To AC Circuit."Additionally, I would make Relay VCC be 5V rather than 3V3 to avoid putting the load of the relay coil on the 3.3V regulator.
Statistics: Posted by alastairpatrick — Tue Mar 05, 2024 1:12 am