Working principle of voltage stabilizing diode
The regulator is regulated by reverse strike zone characteristics of the work, when the zener diode access circuit, if the power supply voltage fluctuations, or other causes in the circuit the voltage changes, voltage across the load will remain basically unchanged. Therefore, the regulator tube to reverse connection in the circuit. The reverse breakdown voltage of the stable voltage tube is called the stable voltage, and the stable voltage of different types of voltage stabilizing tubes is different.

If the grid voltage rises, the output voltage Usr of the rectifier circuit also increases, causing the load voltage Usc to rise. Because of the DW regulator and Rfz Usc load in parallel, as long as there is a little less root growth, the Zener Current will increase sharply, the I1 also increased, limiting resistance voltage drop on R1 increases, thus offsetting the increase of Usr, the load voltage Usc basically remained unchanged. Conversely, if the voltage is reduced, cause Usr decreased by Usc also decreased, the current regulator in the I1 decreases sharply decreased, the R1 pressure drop decreases, which offset the decline in Usr, load voltage Usc basic remain unchanged. If the Usr does not change while the load current increases, the voltage drop on the R1 increases, resulting in a drop in the load voltage Usc. Usc as long as a little bit down, the voltage regulator in the current quickly reduced, so that the pressure drop on the R1 to reduce again, so that the pressure drop on the R1 basically unchanged, so that the load voltage Usc stable.

Zener diode reverse series
1, usually in the larger power amplifier circuit, power transistor base B and emitter e transmitter junction parallel to the two reverse voltage regulator diode, which is through the emission junction input current shunt role and play a protective role.

2, after the series of two zener diodes connected in series to the parallel circuit can play overvoltage protection, when the circuit overvoltage, zener diodes first breakdown short-circuit.

3, two-way overvoltage protection. This double TVs tube, bidirectional overvoltage protection circuit for electronic circuit, and parallel PN junction protected, protect the PN from reverse voltage.
Function: overvoltage protection, electrostatic protection, voltage clamp, damping action.