[Arao] wanted to measure the RPM of a spinning wheel using parts that he could scavenge from his junk box. A bit of thought led him to build a reflective sensor which can measure the spinning of a ...

Let's start with DC voltage, one of the simplest and most-used multimeter measurements. The DC voltage measurement is used to determine the difference in electrical potential between two points in a ...

Craig brought 15 years of automotive journalism experience to the Cars team. A lifelong resident of Michigan, he's as happy with a wrench or welding gun in hand as he is in front of the camera or ...