BJT Current Limit

139

01:10:30

Reference to https://www.youtube.com/watch?v=VJJuxQk5fTY&t=886s

I was thinking that the Ic=B*Ib is the maximum suppliable current, and the actual current flow depends on on the resistor before the LED. 

Thus I was confused when he assumed that the current flow was at Ic or maximum. 

It turns out the circuit would have drawn more current if not for the BJT, and it was current limited by the BJT.

Changing the base resistor to 1KR to allow for a massive 5.2mA current to flow through only result in Ic being 3.95mA, this time current limited by the LED resistor.

published 3 years ago

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