Thanks ericgibbs, You are right. I checked the biasing and I found the mistake.hi M39,
Welcome to AAC.
I would check the Base biassing , the Collector voltage is limited close to saturation.
Measure the Base voltage and Collector DC level without an input signal, what do you measure.?
Thanks Bertus, the link you suggested helped. I checked the biasing and I found the mistake.Hello,
The bias is not correct.
Have a look here for more info on the calculations:
Hi,Can you explain why the absence of base to ground resistance is producing a sin wave which is not perfect. What can be the possible explainination?
Yes I understand it now! Thanks!Hi,
Look at this plot, no 12K to Base,
What is the typical turn on Base voltage of a NPN transistor.???
The Quiescent Base Bias voltage/current is too high a value and the transistor is driven almost into the Collector voltage saturation mode.
The 12k reduces the Quiescent Base drive, so the collector is at approx Vcc/2
Do you follow.?
Distortion of the waveform.The peak values of negative and positive peaks are different, positive peak is 95 mv while negaitve peak is -98mv. What could be the possible reason for this difference in magnitude ?
Thanks Audioguru again! Your given information is helpful.The 2N3904 has a typical hFE of 230 then the base current in the 150k base resistor causes clipping.
The OP discovered that it does not clip when the base resistor value is increased to 1M.
I simulated that using a transistor with less hFE also prevents the clipping.
A high ambient temperature also will probably cause clipping with the 1M base resistor.
The OP needs to see why negative feedback is used so that any passing Vbe or hFE in a transistor will prevent clipping and also prevent the distortion that was mentioned. A voltage divider for the base voltage as shown and an emitter resistor are usually used.
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by Jake Hertz
by Jake Hertz