What's the current through Rbias?
This current must be matched by the current through Q1 by manipulating the trimmer (s?).
Can you vary Vgs of Q1 with the trimmers? What happens to Vgs Q1 when you change the trimmers?
What is the variation in V/2 that you can get, if any?
Measure, measure!
Jan
This current must be matched by the current through Q1 by manipulating the trimmer (s?).
Can you vary Vgs of Q1 with the trimmers? What happens to Vgs Q1 when you change the trimmers?
What is the variation in V/2 that you can get, if any?
Measure, measure!
Jan
Interesting diagram, I had never seen it yet I looked at a lot of andrea's diagrams, I like it.
Are there important things to respect for its realization ?
Are there important things to respect for its realization ?
I'll try to change the trim, but what I wanted to know is if it's the right method of measuring V/2
Should be. But what is it? What is the voltage across Rbias?
I am not asking these questions out of curiosity.
I am trying to point to a quick way of diagnosing the problem.
Jan
You have not said how you are measuring V/2.
Since this plan is ground-at-top it is confusing. Be specific. Answer Jan's questions. Show pictures.
Simplest way:
Whether output is measured to psu positive or psu negative: 25 volts, whether positive or negative, should be measured.
When you do use 27 V as supply, then you should measure 13,5 V at the output.
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as soon as possible I will measure the R bias voltage. That's the design http://www.audiodesignguide.com/PowerFollower/index1.html
Which attachment?
And what did you measure as bias voltage?
Look, do you realize that the current at the bottom pulls V/2 down? That the top FET current, which you set by the trimmer, pulls V/2 up?
So if V/2 is out of range, the issue is betwen the two currents, and that you need to do some measurements to find the cause and fix it?
You want us to bend over backward to help you, yet you can't be bothered to be clear and help us help you.
For some reason you totally refuse to act as an intelligent being. Are you a robot? If so, you need servicing.
I'm out.
Jan
And what did you measure as bias voltage?
Look, do you realize that the current at the bottom pulls V/2 down? That the top FET current, which you set by the trimmer, pulls V/2 up?
So if V/2 is out of range, the issue is betwen the two currents, and that you need to do some measurements to find the cause and fix it?
You want us to bend over backward to help you, yet you can't be bothered to be clear and help us help you.
For some reason you totally refuse to act as an intelligent being. Are you a robot? If so, you need servicing.
I'm out.
Jan
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Don't worry, I said I'll take the measurements as soon as I can. You don't have to solve the universe's problems. thank you