BJT negistor - negative resistance

110

01:45:40

This small two NPN BJT active circuit forms a sweet nice little negistor (negative resistor): the V-I curve has a section with a negative slope. 

Another way to look at it: almost everywhere, the circuit behaves like a resistor an obeys ohm's law: when voltage increases, so does current, and linearly.

 But in a region around 4.5V, as voltage increases, current actually *decreases*.

published 10 years ago

hurz

9 years ago

Place for the ac source a 4.75V DC one and replace the ampmeter with a tank circuit e.g. 500pf 47uH and you have a 1MHz oscillator. Keep it up.

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.