Estimate small capacitors. The test pen can roughly estimate the capacitors from a dozen picofarads to a few tenths of a microfarad. At first, you can see the capacitor charging process in which the light-emitting diode inside the test pen glows and gradually goes out. By observing the brightness of the light and the length of time it is on, the capacity of the capacitor can be judged. the size of. The larger the capacity, the higher the brightness, and the longer the light time, and vice versa. If the light-emitting diode inside the test pen is always on, it can be judged that the capacitor has a breakdown short circuit or leakage; if the light-emitting diode inside the test pen is always off, short-circuit the two feet of the capacitor (discharge) or replace the capacitor pins and test again, such as If it still does not light up, it can be judged that the capacitor is internally open. Because the magnification of the test pen circuit is very high, it is more sensitive to use it to measure small capacitors than to use the multimeter "R×lKΩ" block. In addition, if the capacitor leaks a little, the light-emitting diode inside the test pen will always emit light. However, it should be noted that electrolytic capacitors cannot be tested with a test pen.
