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Design >> Analog Design >> diode circuit
https://designers-guide.org/forum/YaBB.pl?num=1351428479

Message started by aman gupta on Oct 28^th, 2012, 5:47am

Title: diode circuit
Post by aman gupta on Oct 28^th, 2012, 5:47am

please tell the output voltage mathematically or graphically

Title: Re: diode circuit
Post by raja.cedt on Oct 28^th, 2012, 10:38am

hello,
please find the attached plot.

Thanks,
Raj.

Title: Re: diode circuit
Post by aman gupta on Oct 28^th, 2012, 12:06pm

@raja what is the Vo at the point of change of slope ?
In book it is 4.65 V
My approach :
as long as the Vi is < 9.3 V , the diode D1 will be ON because in that case V_A will be < 10 V and current can flow through 10k resistor. And if this is true then D2 will also be 0N and Vo = Vi.
Now second interval i.e Vi > 9.3 V, same reasoning for D3 i.e D3 will be ON as long as Vi > -9.3 V & D2 is ON & D4 is also ON. But in this case if we track from input to the output through D3 & D4 , then i get Vo = Vi and this is making D1 ON which i assumed to be OFF. Summarizing my results :

0<Vi<9.3 all diodes are ON & Vo = Vi
Vi>9.3 all diodes are ON & Vo=Vi..... but this is not possible because this makes V_A > 10 which shows current can't flow from +10V battery. So in short i know i am doing but the question is where ????

Title: Re: diode circuit
Post by boe on Oct 29^th, 2012, 12:08pm

Aman gupta,

if you can work out what the voltages at nodes A and C are, you should be able to answer the question.

- B O E