The schematic legend should read “R3 110” not “3 110.” The same for R4 which appears as “4 110.” We do love unusual ways to use a 555. If you need to read ESR, and you have one of ...

Now, let’s try to use the new circuit of the 555 for something useful. The measurement of a capacitor’s equivalent series resistance (ESR) may become a problem since the ESR can be very low, about ...