# Design a clipper circuit with a specific output

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1. Mar 25, 2016

### Hassan Raafat

1. The problem statement, all variables and given/known data

2. Relevant equations

Clippers equations
3. The attempt at a solution
I knew that we will put a two diodes( with a dc battery {2.3 V} series) parallel to each other in opposite directions .. but what meant by gain is 0.95 ?

2. Mar 25, 2016

### Staff: Mentor

It means that the voltage divider that you form with your series resistor and the load resistor should not drop more than 5% of the input voltage when the diodes are not conducting. Can you show us your solution circuit now?

3. Mar 25, 2016

### Hassan Raafat

4. Mar 25, 2016

### Hassan Raafat

http://blob:https%3A//www.physicsforums.com/e4a89897-2c3c-46b3-8433-735549d386cb

5. Mar 25, 2016

### Staff: Mentor

Good! Now you just have to calculate the input resistor value so that the output voltage is 0.95 * Vin...

6. Mar 25, 2016

### Hassan Raafat

Camera is not good , I can't upload complete solution but R has a value R=52.63

7. Mar 25, 2016

### Staff: Mentor

Can you show your equations that you used to calculate this value? It looks about right, but it would be good to see how you got it. Just type it in here... Thanks.

8. Mar 25, 2016

### Hassan Raafat

http://20160325_192231.png [Broken]

Last edited by a moderator: May 7, 2017
9. Mar 25, 2016

### Hassan Raafat

http://20160325_192231.png [Broken]

Last edited by a moderator: May 7, 2017
10. Mar 25, 2016

### Staff: Mentor

Yeah, the pictures are not showing up. Can you just type it with text into the forum window?

11. Mar 25, 2016

### Hassan Raafat

Vout = ( 1k / (1k+R) ) * Vin
Vout / Vin = 1k / (1k+R)
0.95 = 1000 / (1000+R)
R = 52.63 ohm

12. Mar 25, 2016

### Staff: Mentor

Great!

13. Mar 25, 2016

### Hassan Raafat

Thanks a lot , Berkeman .... You are great :)

14. Mar 25, 2016

### Hassan Raafat

but I still have a question what is the waveform of input voltage ?

15. Mar 25, 2016

### Staff: Mentor

Oh, that wasn't part of what you posted in Post #1. The output waveform will just be a clipped version (and 95% of) the input waveform. What kind of input waveform are you supposed to use? Sine wave? Ramp?

16. Mar 25, 2016

### Hassan Raafat

sine wave

17. Mar 25, 2016

### Staff: Mentor

Of what amplitude? You should be able to draw the input and output waveforms...

18. Mar 25, 2016

### Hassan Raafat

that means that the output will be a sine wave with a peak equals (100/95) * 3 , right ?

19. Mar 25, 2016

### Staff: Mentor

Not exactly. The gain Vo/Vi = 0.95, and the Vo waveform clips at +/-3V.

20. Mar 25, 2016

### Hassan Raafat

Am I supposed to draw input in design circuits ?

And how I determine output without knowing what is the input of circuit ?