Please help analyze the role of this voltage regulator diode in the circuit!

wzk198005

Please help analyze the role of this voltage regulator diode in the circuit! [Copy link]

Hello everyone! As shown in the figure: What is the role of the 2.7V Zener diode in the circuit? Thank you

wangerxian

Prevent excessive voltage from breaking down the diode?

But why put it in that position?

UUC

In electronic circuits, the positive pole of a diode is connected to the low potential end, and the negative pole is connected to the high potential end. At this time, almost no current flows through the diode, and the diode is in the cut-off state. This connection method is called reverse bias.

The breakdown voltage of the PN junction in the diode is used to achieve the purpose of voltage stabilization. When the reverse voltage is higher than the breakdown voltage of the PN junction, the diode is broken down, which is equivalent to a short circuit. The circuit behind the diode acts as a voltage divider, so the voltage is reduced. When the reverse voltage is lower than the breakdown voltage, the PN junction recovers, and the cycle repeats over and over again to achieve a voltage stabilization effect.

chunyang

The voltage drop is equal to the junction voltage drop of the LED plus the breakdown voltage of the Zener tube. However, this method is not good because the parameter discreteness is too large. It is better to use current drive or series current limiting resistor without using Zener tube.

zhuzicheng

To prevent the shot from being too strong, 24-2.7=21.3V, the average point is 21.3/7=3V.

yangyyf

I personally think that LED1 to LED6 are LEDs of one color, and LED7 is another color. Different color LEDs have different operating voltages.