In LM393 datasheet it’s connected to GND on LOW, and disconnected of everything on HIGH. But on my tester I see on LOW: 100 Ohm when no load’s GND connected to Out pin. (No load at all). 850 Ohm when 12V led’d GND lead connected to LM393 out pin.
When I connect the GND of my (comparator-gated) PCB to the out pin nothing 12V fires up, only some 5V leds light up
Why? I expected zero Ohm on LOW. LM393 usage: Big picture: Fix (black): Edit: @justme, I had to use the comparator as a gate driver, was forced to invert the inputs as the MOSFET was always on in the original setup. Driving the gate with 4V; 0.1mA Thanks for the help!