I have a 12V, 15A power supply. Using a multimeter I found that there is continuity between the output terminals (2 positives and 2 negatives) of my power supply. Also, I did the same test on my RAMPS (RepRap Arduino Mega Polulu Shield) 1.4 and I found that there is continuity in the first three terminals(negative, positive & negative) with each other but not in the fourth(positive).
Why is there continuity between the negative and the positive terminals of both the RAMPS and the power supply? Furthermore, why is there continuity on RAMPS with only b/w one positive and the two negative terminals and not with the second positive?
Just a side note my multimeter does not beep when I connect the negative and the positive terminal on the power supply (only shows some value) but does sometimes beeps in the ramps 1.4 (along with a value).