You would like a circuit to create a voltage that you can measure that is proportional to your load current. What circuit would you use? There are many circuits to measure current. One common approach ...

If you want to measure resistance and you know Ohm’s law, it seems like you have an easy answer, right? Feed a known current through the thing you want to measure and read the voltage required. A ...

The improved one-BJT current-limiting supply is not much different than the primitive circuit, though its one additional resistor does change the circuit behavior. The improved circuit is shown below.

To calculate the resistance of the series resistor required, we need to look at the current and voltage values recommended by the LED manufacturer. Suppose a manufacturer recommends a maximum voltage ...