Demystifying Negative Resistance: How Circuits Can Generate Power
I explore the counterintuitive concept of negative resistance, where a component appears to generate energy rather than dissipate it. While physical resistors always consume power, I explain how operational amplifiers can create circuits that mimic negative resistance by backfeeding current. This analysis clarifies the physics behind the phenomenon and demonstrates a practical circuit design that achieves this effect within specific voltage limits.
If R is negative and I = V / R, then the current-to-voltage plot will have a downward slope, implying that the component would need to extract energy from its surroundings and put it back into the circuit.
- DivingForGold
Great to see this discussion. My son displayed a science project on negative differential resistance 21 years ago. Had quite a few electrical engineers passing by with "the low brow" look. His device involved carbon fibers arranged in a cross shape placed inside of a cement mixture and compressed to ~8,000 psi during the cure stage (following the example of some published research).
- arjie
I think it is very funny that the author has decided to start with a layman’s introduction to the concept of resistance after saying that you need familiarity with the behavior of operational amplifiers. Who is in that category of familiarity while still not having an intuition for resistance? Perhaps someone but how.
- inigyou
a.k.a. electrical oobleck