So I found this amplifier alike box at some other departments scrap box, free for take away:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170063.JPG)
Wondering what purpose it served, asking a colleague, I was told it was used to characterize some inductive components. Turns out, it's a power amplifier with some additional control loop circuitry (most left cabinet) and a bit of fan control and overload shutdown (right next to the heat sink). Most right is a power supply for these
auxiliary circuits. But no power supply included for the amplifier stage itself. At the same place I found some industrial SMPS, rated at 48V / 5A, two of them made up a useful supply for the amp.
Now isn't this a perfect excuse to show some of my TEA in action?
First thing we need is a serious load resistor. This heat sink and the attached resistors usually sit stashed away in the cellar, since I rarely use them:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170056.JPG)
Of course, we want to know what is the input power to the amplifier:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170054.JPG)
And for sure, we want to know the output power:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170055.JPG)
And the output voltage / current waveforms (didn't need to use a current clamp here, as the amplifier has a built-in shunt and sense amplifier):
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170053.JPG)
Does a nice square wave also:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170057.JPG)
Doesn't look too much TEA alike inside:
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170058.JPG)
![](https://cb.wunderkis.de/wk-pub/amplifier/P1170060.JPG)