# Circuit with diode

1. Apr 14, 2013

### pyroknife

I attached the circuit.
I need to find I_1, Voltage drop across R1, voltage drop across R2, and I_2. We're assuming the diode is 'not' ideal.

Vin=5V. R1=R2=1kohm
R3=2kohm

voltage across R2=Vin=5V
I2=5/1kohm=5mA

The real diode drops about 0.7 V. So using voltage divider gives voltage across R1=(R1/(R1+R3))*(5-0.7)=1.43V

Then I1=1.43/1k=1.43mA

Is this the right idea?

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2. Apr 14, 2013

### phinds

without comment on the correctness of your specific numbers, let me ask you this:

Do you feel that I2 = 5m in the same sense that I1 = 1.43ma. That is, other than magnitude, would they have the same waveform if graphed?

3. Apr 14, 2013

### pyroknife

I guess I don't see what you're asking.
This is a DC signal.

For an AC signal, the would not have the same wave form due to the diode.

4. Apr 14, 2013

### phinds

Hm ... why do you suppose a DC source is labeled "Vin, VAC ?"

5. Apr 15, 2013

### pyroknife

Ignore the AC part, that's for another problem.