I need to power up a make-or-break simple automotive relay (4pin, 40A 12V) via an OR gate.
OR gate as follows:
- Source 1 is the cable that provides +12V to activate car dome light which I will tap into and
- source 2 is engine-on port from the busbar, obviously +12V when engine is on.
So if the dome light is on OR if the engine is on, the relay will activate.
I understand I need to put one way diodes on both my sources and connect them to pin 85 of the relay. What type of diodes I need to purchase?
EDIT automotive relays have standardized pin numbers ie in this case a 4 pin relay has pins 30, 85, 86, 87