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What is the purpose of series resistance in zener diode voltage regulation circuit?
Zener diode operation As the reverse voltage increases to the predetermined breakdown voltage (Vz), a current starts flowing through the diode. The current increases to a maximum, which is determined by the series resistor, after which it stabilizes and remains constant over a wide range of applied voltage.
Why does a zener diode need a resistor?
The Zener diode provides the reference voltage, but a series resistor must be in place to limit the current into the diode otherwise a large amount of current would flow through it and it could be destroyed. Typically most low power leaded Zener diodes have a maximum power dissipation of 400 mW.
How zener diode can be used as a voltage regulator?
Zener diodes are widely used as voltage references and as shunt regulators to regulate the voltage across small circuits. When connected in parallel with a variable voltage source so that it is reverse biased, a Zener diode conducts when the voltage reaches the diode’s reverse breakdown voltage.
How does the voltage regulator work in a Zener diode?
The zener voltage regulator consists of a current limiting resistor RS connected in series with the input voltage VS with the zener diode connected in parallel with the load RL in this reverse biased condition. The stabilized output voltage is always selected to be the same as the breakdown voltage VZ of the diode.
Which is better Zener diode or filter capacitor?
The Zener diode offers a much higher stabilization level (power supply) than can be achieved with a bridge rectifier circuit and filter capacitor.
Which is the upper limit of the Zener current?
There is a minimum zener current for which the stabilisation of the voltage is effective and the zener current must stay above this value operating under load within its breakdown region at all times. The upper limit of current is of course dependant upon the power rating of the device. The supply voltage VS must be greater than VZ.
What is a filter in a voltage regulator?
Filter: a circuit used to reduce the fluctuation in the rectified output voltage or ripple. This provides a steadier