Some more info:
I measured the voltage available for the meter circuit at low and high power
With 60W DC input I have around 3 V and with 400W DC input this goes up to
around 9 - 10V
My meter is 10mA full scalle. With 53mV I have full scale reading , so
internal resistance around 5 Ohm.
So, with around 26.5mV I have 5mA reading.
So my meter should read around 0.5mA at 60W DC input (=3V from detector) and
about 3.5mA at 400W DC input (9V)
These are rough figures.
So, I'm looking for a circuit that can do the right "transformation" so to
Maybe it should something with an op amp.
I do have plenty of TLC271 (is offset programmable TL071) in my junkbox, or
use something else.
Hopefully someone comes along with a schematic.
Finally it doesn't have to be a circuit with very precise measuring, but a
rough indication +/- 50W would