Hi all,
The circuit shown below is what I have constructed
Now firstly, the -Supply is connected to ground with a supply voltage of around 16V. Now I have replaced the BC549 with both a BC548 AND a 2N3904. I have tested this circuit in LTSpice with different transistors and it works as expected.
So why in real life does it not? If I connect the output to the inverting input I should have a unity gain buffer. But what I get instead is a unity gain buffer that matches the input up to 1.8V or so but after that point up to some higher voltage the output is constant. Then when the input approaches the supply voltage the output quickly shoots to meet the current input voltage. Its like there is a range of values for which the output just stays fixed. Any reason why? Does this circuit only work in theory or am I just mad?
All the best,
Robin
The circuit shown below is what I have constructed
Now firstly, the -Supply is connected to ground with a supply voltage of around 16V. Now I have replaced the BC549 with both a BC548 AND a 2N3904. I have tested this circuit in LTSpice with different transistors and it works as expected.
So why in real life does it not? If I connect the output to the inverting input I should have a unity gain buffer. But what I get instead is a unity gain buffer that matches the input up to 1.8V or so but after that point up to some higher voltage the output is constant. Then when the input approaches the supply voltage the output quickly shoots to meet the current input voltage. Its like there is a range of values for which the output just stays fixed. Any reason why? Does this circuit only work in theory or am I just mad?
All the best,
Robin