Common Emitter Amplifier - Practical Build (2/2)

[@alaricsnellpym]

I've recently been putting together some common emitter and common collector amplifiers as part of an audio project, so it's been nice to watch some videos that take a different perspective on something I already just about know, reinforcing my understanding and boosting my confidence!

[@soothcoder]

I have an older siglent sig gen but a low end keysight scope. The scope can do automated phase and peek-to-peek measurements. You can control the sig gen over usb and likely the scope too. With a bit of python you could automate your measurements and even do log plots. I ran into issues when the signal is low as then the phase is a guess. I also find I had to adjust the scope (with my python) so the signal filled the screen. It’s a bit fiddly but you will use the code again.

[@FesZElectronics]

The oscilloscope I have can also do phase shift measurement, but it just could not accept the "Math" as input; I never really worked with python, and I'm not much a programmer in general, but I do agree, if you can use some control commands over USB, a lot of measurements can be automated and performed with ease

[@bingcheng8419]

When doing the impedance measurement, if you make a Bode plot sweep, can the result used to calculate the impedance? First convert the Bode plot curve to complex form, let's say "A", Then use 1 minus the ratio "A" to get the voltage across the series resistor. So the current to input ratio will be (1-A)/R Lastly, the impedance will be A/(1-A)*R

[@TheGmr140]

Nice experiment

[@anlpereira]

Hi, in a world where almost every source or load is intend to be 50Ohm impedance, why use an amplifier with almost 10k or 2kOhm input impedance? Thank you very much.

[@FesZElectronics]

50ohm is common for RF equipment and for coax transmission lines, but its not the only value possible - 75ohm is also common for coax and 100ohm is common for differential lines; things like microphones are usually high impedance (2-10k) and things like speakers are very low impedance (4-8ohm); In the end, the best impedance is use case dependent.

[@anlpereira]

@ So, for a RF amplifier it would not be recomended to have a high input impedance because of the high reflection coefficient? Thanks again.

[@akashkedia4618]

Sir, please make a video on how to make an almost ideal pulse transformer for isolated power electronics converters (like DAB).

[@t1d100]

Good stuff.