Hey, i'm sorry for not updating you about it.R2 = 150 ohm; (4.7 - 1.99)/150 = 18mA
R2 = 75 ohm; (4.7 - 2.92)/75 = 23mA
R2 = 25 ohm; (4.7 - 4.02)/25 = 27mA
The current is tighter than you think. Have you thermally coupled T1 and T2? If not, then do so.
Your error calculation is wongOh I see.
Do you think that its that crucial? (an error of 38.9mA/26.8mA * 100 = 145%).
How do you thermally couple the transistors please?
Thank you for your help and guiding.
No, I'm saying all current mirrors need to be thermally coupled. One transistor cannot be coupled, obviously. There are other methods of stabilizing a single transistor amplifier.Are you saying that all amplifiers are thermally coupled so their bias point wont be effected by different loads?
I'm still not sure how to have it thermally coupled (one transistor for example).
You can't. You need some form of active feedback to do that.Yes I understand.
The thing is that i'm talking about having only a single mosfet, driving its gate with a constant voltage from a PSU to get it saturated, and changing its load, hoping to see a constant current for different loads.
I'm afraid that i wont see constant current for the same reason IDS2 was different for each load (while VGS2 remained constant).
So my question is, how do i get the current of a single saturated transistor not to change for different loads?