barry
" Also, transistors are current, not voltage, devices. It’s not the voltage AROSS the base that controls the collector current; it’s the current into to the base that matters.
Let me explain why you are wrong about that statement. It's all in the physics. A BJT NPN transistor operates by diffusion, which causes charges to flow by diffusion from the emitter to base and onward to the collector and circuit by the positive collector voltage. But the electrons leave behind charged ions which counter the flow of electrons. Applying a positive base voltage counters this effect and speeds the electrons on their way. However, some the the electrons that should go to through to the collector are attracted into the base circuit by the positive voltage. This is wasted current. By happy fortune, the collector current is a fairly constant ratio of the base waste current called "beta" . Now you can hook up a current generator to a transistor and plot some useful curves and think you have a current controlled device. But you are fooling yourself. You have a current controlled CIRCUIT. The virtual resistor of the current generator is part of the circuit. The transistor itself still dances to the voltage it receives from the current generator. A transistor is voltage controlled.
Another example. No one denies that an ordinary op-amp is a voltage amplifier. Yet, within the proper circuit circuit it can be part of just about anything else. A device that is truly current controlled is a magnetic amplifier. They are big, ugly and rugged compared to solid state.
Ratch