
	Home


	Homework Help


	Answer Board


	Resources (Beta)

You Are Here:

Home > Answer Board > Electrical Engineering > Topic: Find the value of R for which V=80mV

Member's Topic Headline:

Find the value of R for which V=80mV

Know the answer? Have a better solution? Share it.

Get Help Now.

View homework problems
explained for free!

Question:

Shree_vani

Oracle

Karma Points: 9,262

Date Posted: 7/22/2008 12:29:46 PM Status: Live

Asker's Rating: None Provided Moderator's Rating: Lifesaver

Response:

When the diode voltage V_D1 = 0.7V, the current through it is I_D1 = 10mA

When the diode voltage V_D2 = 0.8V, the current through it is I_D1 = 50mA

Hence the diode resistance is given by

Since the diodes are identical

The forward resistance of D1 = r_f1 = 2.5Ω

The forward resistance of D2 = r_f2 = 2.5Ω

Now applying current divider theorm, current through D₁ and R is

The voltage across the resistor R is

With V=80mV = 0.08V

The reistance value should be R=2.35Ω

By reading or posting messages on these forums, you are agreeing to the Answer Board's Terms of Service and Conduct (TSC).