Transistor explained in terms of diodes

131

02:16:18

Transistor is can also be viewed as 2 diodes 
Like in the circuit 2 diodes are used in a way so that negative sides of diodes are joined together to form a PNP junction

published 4 years ago

Robert_Kidd

4 years ago

In physical terms it can be viewed as two diodes. In operation it cannot! You are using approx. 150mA to switch an LED on which consumes approx. 20mA. That’s a negative gain! With a real transistor you’d only use, perhaps, 0.2mA to switch the LED on (assuming a forward gain (hfe) of 100).

Robert_Kidd

4 years ago

Further, the 1V supply is connected back to front. If you reverse it you’ll see the current in that path drops to around 20mA. The gain is then approx. 1.

Robert_Kidd

4 years ago

Even those changes don’t make the circuit representative of a transistor.

slm67

4 years ago

What happens is that when you close the switch, the two power supplies and the LEDs are connected in series!

slm67

4 years ago

in fact, this circuit will not work.

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