Wemos D1 Mini - Help me select transistor / mosfet for a 12V LED strobe

[zamb]

Wonderful, even a schematic!
Thanks for explaining!

Maybe will be combined with this:

D1 Mini + 12V PIR from old alarm system

Hi! Is there a simple way to make an old PIR motion detector “smartified”. It seems to be 4 wires to the old PIR. Please point me in the right direction.