Clamper Circuit and Non-Ideal Diode

A clamper circuit is an electronic circuit that is used to shift the DC level of a waveform. It consists of a diode, a capacitor, and a resistor. When the diode is forward biased, the capacitor charges to the peak value of the input signal and stores this voltage level. When the diode is reverse biased, the capacitor discharges through the resistor, maintaining the stored voltage level.

However, in practical applications, diodes are not ideal and have some resistance associated with them. In this case, the forward resistance and reverse resistance of the diode are given as 200 ohms and 250 kilo ohms, respectively.

Determining the Correct Resistor Value

To correct the circuit, a resistor needs to be connected in parallel to compensate for the non-ideal characteristics of the diode. The value of this resistor can be calculated using the following steps:

1. Identify the desired voltage level: The desired voltage level is the DC level that needs to be shifted to zero volts. In this case, the desired voltage level is zero volts.

2. Calculate the resistance required to shift the voltage level: The resistance required can be determined using Ohm's Law. The voltage across the resistor is the desired voltage level (zero volts), and the current through the resistor is the current flowing through the diode when it is reverse biased.

Using Ohm's Law: V = IR
Rearranging the formula: R = V/I

The current flowing through the diode when it is reverse biased can be calculated using the reverse resistance of the diode. Given that the reverse resistance is 250 kilo ohms and the voltage across the resistor is zero volts, the current can be calculated as:

I = V/R = 0/(250,000) = 0 A

Therefore, the resistance required to shift the voltage level to zero volts is zero ohms.

3. Determine the value of the resistor to be connected in parallel: To compensate for the non-ideal characteristics of the diode, a resistor with a value equal to the reverse resistance of the diode needs to be connected in parallel. In this case, the reverse resistance of the diode is 250 kilo ohms.

However, the circuit designer has already used a 10 kilo ohm resistor in the circuit. To find the equivalent resistance when the two resistors are connected in parallel, the formula for calculating the equivalent resistance of two resistors in parallel is used:

R_parallel = (R1 * R2) / (R1 + R2)

Plugging in the values, we get:

R_parallel = (10,000 * 250,000) / (10,000 + 250,000)
= 2,500,000,000 / 260,000
= 9615.38 ohms

Therefore, the value of the resistor to be connected in parallel to correct the circuit is approximately 9615.38 ohms, which is closest to option 'A' - 24 kΩ.

We have a formula to get the value of resistor to be used in a clamper circuit and it is given by R =