if circuit on the left of terminal A-B are in black box and I want to find Thevenin resister by apply voltage source v1 to the terminal A-B measure current i1 then change voltage source to v2 and measure current i2. But R=v1-v2/i1-i2 = infinity because i1=i2. How can I find Thevenin equivalent circuit?
How can I find Thevenin equivalent circuit?
A resistor in series with a constant current source has no effect. The current source projects an impedance of infinite ohms and any resistor in series with it does not change infinity to anything other than er... infinity.