Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Diode circuit analysis ?

Status
Not open for further replies.

tron87

New Member
In the attached circuit how is R1 and RL calculated ?
 

Attachments

  • diode circuit.JPG
    diode circuit.JPG
    104.5 KB · Views: 243
Since V1 is 10V and the voltage at the tap is 5V, and the current through R1 is 10mA, then R1 = E/I = (10-5)/10m = 500Ω

The current through R2 is I = E/R = 5/5K = 1mA.

The current through the diode& RL must be 10mA-1mA = 9mA (Σ currents into node=0)

The voltage across RL is (5-0.7)=4.3V, therefore RL=E/I = 4.3/9m = 478Ω

btw: your assumption that the forward drop across the diode is 0.700V is a little off. At room temperature, a 1N4148 would have a forward drop of about 0.688V. However, the calculations above are based on 0.7V.
 

Attachments

  • DF130.png
    DF130.png
    15.1 KB · Views: 301
Last edited:
Status
Not open for further replies.

Latest threads

Back
Top