Positive and negative electrodes of Zener diodes and their use

Positive and negative electrodes of Zener diodes and their use.
Also known as Zener diode. A voltage stabilizing diode is made by making use of the reverse breakdown state of the pn junction, whose current can change in a wide range but the voltage is basically unchanged. This diode is a kind of semiconductor device with high resistance up to the critical reverse breakdown voltage. At this critical breakdown point, the reverse resistance is reduced to a very small value, where the current increases and the voltage remains constant in this low resistance region. Zener diodes are graded according to the breakdown voltage, because of this characteristic, the regulator is mainly used as a voltage regulator or voltage reference. Zener diodes can be connected in series for use at higher voltages, and higher stable voltages can be obtained through series connection.
The working conditions of the Zener diode are as follows: the voltage applied to the Zener diode in reverse is greater than the stabilized value of the Zener diodee. The current passing through the voltage stabilizer should reach its working conditions.
Selection of current limiting resistance of voltage stabilizing diode circuit: if R is too large, the Ir is very small, when the Il increases, the current of the voltage regulator may decrease below the critical value and lose the voltage stabilizing effect; if R is too small, the Ir is very large, when the Rl is very large or open, the Ir flows to the voltage regulator, which may exceed its allowable quota and cause damage.