There are (probably) less than two dozen fundemental constants that define the physics of our universe. Determining the value of them might seem like the sort of thing for large, well funded ...

To measure a zener diode’s breakdown voltage, you need a dc voltage source whose voltage exceeds that of the zener voltage. In Figure 1, resistor R SER provides voltage drop between V IN and V ZEN. In ...

So a few months ago, I stumbled upon a thing at Adafruit.com called a "Charger Doctor" which was really just a Multimeter designed to slip inline with your USB cable. It was $7.50 and I liked it.

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? A digital multimeter is an indispensable tool for testing, diagnosing, and ...