Can you identify a regulator diode?

Will you identify a regulator diode?

regulator diode are often marked with "ZD" plus numbers in circuits, such as ZD1 indicating a regulator diode with number 1.

Positive and negative pole identification

From the appearance point of view, the positive end of the metal package regulator diode diode body is flat, and the negative end is semi-circular face. One end of the plastic regulator diode body printed with colorful symbols is the negative pole and the other end is the positive pole. For the voltage regulator diode with unclear mark, you can also use a multimeter to determine its polarity, and the measurement method is the same as that of general diodes, that is, use a multimeter R × 1k gear, the two pens are separated from the two electrodes of the regulator diode, and after measuring an effect, the two pens are measured. In the two measurement effects, the time when the resistance value is smaller, the black pen is connected to the positive pole of the regulator diode, and the red pen is connected to the negative pole of the regulator diode.

Color ring regulator diode identification

Color ring regulator diode are rare in China, most of them come from abroad, especially Japanese products. Generally, color ring regulator diodes are marked with types and parameters, and detailed information can be found in the component manual. The color ring regulator diode is small in size, small in power, and the voltage regulation value is mostly within 10V, which is easy to break down and damage. The appearance of a color band regulator diode is very similar to the color band resistor, making it easy to make a mistake. The color ring on the color ring regulator diode represents two meanings: one is to represent the number, and the other is to represent the number of decimal places (generally the color ring regulator diode takes one decimal place and is marked with brown. It can also be understood as the magnification is: ×10 (to the power of -1), and the digital color ring resistance corresponding to the detailed color).

The difference between a regulator diode and a general rectifier diode

First, use the multimeter R×1K block to identify the positive and negative electrodes of the diode under test. Then dial the multimeter to R×10K block, the black meter pen is connected to the negative pole of the measured diode, and the red meter pen is connected to the positive pole of the measured diode, if the reverse resistance value measured at this moment is much smaller than the reverse resistance measured by R×1K block, it means that the measured diode is a voltage stabilized diode; Conversely, assuming that the measured reverse resistance value is still large, it means that the diode is a rectifier diode or detection diode.

The reason for this identification method is that the battery voltage used inside the multimeter R×1K block is 1.5V, and it will generally not be broken down by the reverse of the diode, so that the measured resistance value is relatively large. When R×10K gear measurement, the voltage of the battery inside the multimeter is generally above 9V, and when the diode under test is a voltage regulator diode, the cutting voltage stabilization value is lower than the battery voltage value, that is, it is reversed breakdown, so that the measured resistance value is greatly reduced. However, assuming that the diode under test is a general rectifier or detection diode, regardless of the R×1K block measurement or the R×10K block measurement, the obtained resistance value will not be very different. Note that when the regulated value of the regulator diode under test is higher than the voltage value of the multimeter R×10K stop, it is impossible to distinguish the difference with this method.