The output will always receive a voltage which is dependent on the rating of Zener diode. When forward biased, it behaves like a normal signal diode, but when the reverse voltage is applied to it, the voltage remains constant for a wide range of currents. When selecting zener diode voltage, one should remember that emitter voltage will be lesser than zener voltage by an amount equal to base emitter voltige minus 0.6 volts, for Silicon transistor. Even if this seems to be problematic, you can use an emmitter-follower circuit to buffer zener-diode and enhance the current ability.If we make best use of Zener diodes, they can deliver highest performance. The variations make happen by load may be minimized through using follower- emitter- stage to decrease the current availed from zener-diode circuit and as a result the changes it perceives. This website uses cookies to improve your experience. Zenar diode is selected to ensure a voltage value beyond the regular operating voltage – adequate margin which is not fired below regular operating situations, but slight enough to permit current flow rapidly whenever the fault situation is sensed.Under usual operating circumstances the Output-voltage is less than the revers voltage of zener diode and not any current flows through it and this way SCR gate is not afire.On the other hand, if voltage increases above the acceptable voltage, zener-diode will start conducting, SCR will be fired and fuse would be blown.The zener diode is much elastic and advantageous circuit component. This diode operates in zener breakdown or avalanche breakdown, However the word zener is used for all components having sharp breakdown characteristics in reverse direction. Still, similar to other electronic components, there are few clues and hints which empower the best of the zener diode. If a faultless source of voltage was applied to it, it will pass too much current as soon as reaches breakdown-voltage. Zener diodes are semiconductor PN junction diodes with controlled reverse-bias properties, which make them extremely useful as voltage references.
Typically it may be little like balancing in certain circuits as deviations in Load current would affect the Zener diode’s current. We deliver up-to-date correct, authentic data based on evaluation unbiased at no cost to you. A current value of about 5mA should be retained for a usual 400 mw device. this circuit uses a Zener diode to provide a regulated output to the load side, protecting the circuit. The simple circuit diagram is displayed below where the transistor is being used as emitter follower.When using such a circuit, the current needed from the zener resistor potential divider must be calculated.
This zener diode is designed to operate at breakdown region during reverse bias.Here zener breakdown or avalanche breakdown occurs at reverse bias after reaching the breakdown point in terms of reverse voltage and current afterwards zener diode allows constant voltage with different current level.You can use any of these zener diode as a Regulator in your design and put exact Rs Resistor according to the zerner diode and output voltage specifications.In this schematic a 5.1 Volt zener diode is used in reverse bias, when the input voltage increase or above the zener breakdown then zener starts to conduct voltage up to the breakdown voltage level and gives regulated output voltage. We know zener diode is a two terminal active device and specially known for zener breakdown operation. And remember this could demolish all chips which are being powered.This problem can be overcome by using “crowbar circuit”.