From the appearance, the positive end and the negative end of the metal-encapsulated Zener diode body are flat and semicircular. One end of the plastic sealed Zener diode body with color marks is the negative electrode, and the other end is the positive electrode. For zener diodes with unclear markings, the polarity can also be determined with a multimeter. The measurement method is the same as the ordinary diode, that is, use a multimeter R1k, connect the two probes to the two electrodes of the Zener diode, measure one result, and then switch the two probes to measure. In the two measurement results, the black probe is connected to the anode of the Zener diode, and the red probe is connected to the cathode of the Zener diode for the smaller resistance value. This refers to an analog multimeter.
There are few domestic products of color ring voltage regulator diodes, most of which come from abroad, especially Japanese products. The general color ring Zener diode is marked with the model and parameters, and detailed information can be found in the component manual. However, the color ring voltage stabilizer diode is small in size, low in power, and the voltage stabilized value is mostly within 10V, which is easy to breakdown and damage. The appearance of the color ring Zener diode is very similar to the color ring resistance, so it is easy to make mistakes. The color ring on the color ring voltage stabilizer diode represents two meanings: one is a number, and the other is the number of decimal places (usually the color ring voltage stabilizer diode takes one decimal place and is represented by brown). It can also be understood as a magnification, that is, 10 (to a power of -1), the number corresponding to a specific color is the same color ring resistance
Due to the small size of low-power Zener diodes, it is difficult to mark the model number on the tube, so some foreign products use colored circles to indicate their nominal stable voltage value. Like the color ring resistance, the colors of the color ring are brown, red, orange, yellow, green, blue, purple, gray, white and black, which are used to represent the values 1, 2, 3, 4, 5, 6, and 7 respectively. , 8, 9, and 0. Some Zener diodes have only 2 color rings, while others have 3. The first ring is closest to the cathode, followed by the second and third rings. There are only two colored rings. The nominal stable voltage is two digits, namely "V" (tens of volts). The first ring represents the value of the tenth bit of the voltage, and the second ring represents the value of the tenth bit. For example, the colors of the first and second rings are red and yellow, and 24V.
has 3 colored circles, the second and third colored circles are the same color. The nominal stable voltage is a one-digit integer with one decimal place, that is, "xv" (a few points and a few volts). The first ring represents the value of the voltage level. The second and third colored circles (same color) together represent the value of ten digits (the first digit after the decimal point). For example, the colors of the first, second, and third rings are gray, red, and red in order, that is, 8.2V. There are 3 color circles, and the second and third color circles have different colors. The nominal stable voltage is a decimal two-digit integer, namely "x x x v" (a few dozen volts). The first ring represents the tenth digit of the voltage. The second ring represents the number of bits. The third ring represents the value of the tens digit (the first digit after the decimal point). However, this situation is rare. For example, the comparison table of the models of ordinary Zener diodes (brown, black, yellow (10.4 volts) and brown, black, gray (10.8 volts) (Note: The following diode models start with 1, such as 1N4728, 1N4729, etc.).)
The above explanation is the method of judging the positive and negative poles of the Zener diode. I hope it will be helpful to you after reading it. If you want to know more about the Zener diode related information, please contact customer service online or call our company Service hotline (upper right corner of the website) for consultation, we will be happy to provide you with quality service!