- #1
asitiaf
- 21
- 0
How do Zener diode keep voltage constant if input voltage is less than Zener voltage
asitiaf said:How do Zener diode keep voltage constant if input voltage is less than Zener voltage
asitiaf said:I understand that excess voltage will be dropped across Rs, when input voltage is greater than Zener voltage.
But I'm asking will there be any current through RL, if input voltage is less than Zener voltage.
Give reasons for the answer.
Okay.asitiaf said:The diode will not be conducting if input voltage is less than diode voltage.
Vin = (RL+RS)*I
Voltage across Rs = Rs*I
Suppose, first case
Vz = 5V
Vin = 4V
Rs = 2ohm
RL = 6ohm
Now,
I = 0.5 A
Voltage across Rs = 0.5*2 = 1V
And voltage across RL = 0.5*6 = 3V
No, that's not true. Rs and RL form a voltage divider, so the voltage across RL will be less than 5V.Second case,
Vin = 5V
Rest all same.
Now
Voltage across RL = 5V because of the Zener diode
But what will be voltage drop across Rs?
Nope again. The voltage divider situation still exists for the Vin = 6V case.Third case
Vin = 6V
Rest all same
Now
Voltage across RL = 5V
And voltage drop across Rs = 1V
This concludes me that voltage across RL remains 3V in first case and 5V in second and third case.
What type of voltage regulator this Zener diode is, if voltage across load keeps varying.
I am sorry for asking fundamental doubts.
A Zener Diode is a type of diode that is designed to maintain a constant voltage across its terminals, even when there are changes in the voltage applied to it. This is due to its unique construction and properties that allow it to regulate voltage.
A Zener Diode maintains voltage stability by utilizing a process called Zener breakdown. This occurs when the reverse bias voltage applied to the diode exceeds a certain threshold, causing a sudden increase in current flow and allowing the diode to regulate the voltage across its terminals.
Zener Diodes are commonly used in voltage regulation circuits, such as in power supplies and voltage regulators. They can also be used in surge protectors and as voltage references in precision electronic devices.
The key factors to consider when choosing a Zener Diode for your circuit are the breakdown voltage (Vz), the maximum power dissipation (Pd), and the maximum current (Iz) that the diode can handle. These specifications can be found in the diode's datasheet and should be selected based on the voltage and current requirements of your circuit.
Yes, Zener Diodes can be used for voltage regulation in both AC and DC circuits. However, for AC circuits, a bridge rectifier should be used to convert the AC signal to DC before it is applied to the Zener Diode, as Zener Diodes only regulate DC voltages.