Hey guys, I need some advice / help. I've got a pretty simple setup, as I'm in the circuit proof of concept stage.
I've got a 12v power supply, which feeds a 12v to 5v converter to run an Arduino.
I've got a 12v relay, powered by the supply, and passing through 12v on trigger to a 12v solenoid.
I'm triggering the signal wire on the 12v relay (it only requires 3v (tested with bench supply) to trigger the relay), with a GPIO pin. The relay is a "latching" relay, so I just. need a pulse of HIGH and then set back to low on the GPIO pin to put it in the correct state, I don't have to "hold" the relay open with the GPIO.
Here's my diagram.
And the schematic on the relay:
The relay will trigger over and over when signaled from the bench supply...when triggering it from a GPIO, the GPIO is immediately burnt out. Can someone tell me what they think is happening, and how to "measure" and / or "check" for blowback, over draw of current...whatever the case may be, before I keep burning out more GPIO pins.
I should note, that when signaled from the GPIO - the relay never fires, the pin will burn out, and the relay will never trip.
Thank you all for your help in advance.
EDIT: I assume I'm burning them out. After a trigger, they will not go back into PIN HIGH state, and measure no (or very tiny) voltage on the pin.