Simple Circuit Problem

[km]

I have some problem for my circuit below. Suppose at point A, I will get a waveform as shown in the graph below. But, instead of getting the desire results, I got a sine wave ( Vp-p = 3.XX volts ). Actually I manage to get the desire results at the beginning of my test - but after a whille the waveform change into a sinewave with smaller amplitude and remain!. What's wrong with my circuit? Do I need to make any changes? :idea:

 

[John Sorensen]

Well, I don't know what you're trying to do, but the output is being clamped by D1 and D2.

j.

 

[Roff]

One of your diodes may have burned out or become disconnected.

 

[John Sorensen]

I'm confused. Is the simulation above what he wants, and actual circuit doesn't work right, or is he wondering the circuit above doesn't work like he thinks it should.

j.

 

[Roff]

I'm confused. Is the simulation above what he wants, and actual circuit doesn't work right, or is he wondering the circuit above doesn't work like he thinks it should.

j.

John, see this thread.