Pin Judgment Method For 78L05,78L33 Series Voltage Stabilizing ICs

The 78 series voltage regulator IC is the most widely used type in electronic products, and its voltage regulators have the characteristics of simple structure, excellent performance, and no need for debugging. However, due to different manufacturers, the arrangement order of IC pins is often different, and in case of incorrect connection, it is easy to burn the IC.

The first method is to set the multimeter to resistance R × 100 or R × In 1K gear, the black probe contacts either pin of the IC, and the red probe contacts the other two pins respectively. Observe the measured resistance values. If the resistance values measured twice are both large (compared to the resistance values measured by the black probe on other pins) and close, then the pin contacted by the black probe is the input terminal IN. Compare the resistance values measured twice. In the measurement with the smaller resistance value, the red probe contacts the ground terminal and the other pin is the output terminal OUT.