Below is a childish question, but first as a hide-and-seek lead-in to that, there is also a provocative and largely neglected old page on the JNL site:
http://jlnlabs.online.fr/cnr/negosc.htm This page concerns an unacknowledged feature (not mentioned by the manufacturer) of a certain transistor, operating *in reverse mode* as a NDR oscillator. The Negative Differential Resistance (NDR) effect is seen in other devices like the Gunn diode and even the fluorescent tube, but is NOT normally even close to an overall overunity effect (sorry) ... at least not in isolation; and the net effect of any part with an NDR range is still lossy, especially for circuits with one or a few parts... ...but yet on a deeper level: this device does not seem to agree with the basic premise of Ohm's Law, which makes one wonder why it is a "law" and not a hypothesis. According to the Ohm's law, an increase of voltage should produce an increase in current. In this 'case' (pun intended), and in the negative resistance region of the 2N222A curve, an increase of the voltage produces a decrease of the current, but only when in a can. Yawn.... Some few have recognized that within its narrow range of voltage, *NDR is a kind of RTS* or even better, but the inverse situation is what is most provocative. Wow - NDR = RTS ! How is that for matching arcane-acronyms? BTW -- RTS = room temperature superconductivity. The 2N2222A is an older NPN bipolar part and usually found only in the TO-92 (plastic) case, but which is still to be found on occasion on eBay in 'a can' (like poor Prince Albert) designated as the TO-18 part ... ... not sure if it is still in production: that is, in production in the metal can instead of the plastic potting, which is much cheaper to make. *Only* the metal can works in reverse mode as a "negistor". Bizarro! Don't know if this is relevant to the $64 question, but the TO-18 is a much smaller part than the TO-92. OK Here is what you have been waiting for: the aforementioned $64 question: Why is only the 2N2222A in the TO-18 can functioning in the NDR range, and not the very same part in a plastic case !?! Jones Any good answer will result in a bequest in my will for at least $64... and that might be forthcoming sooner rather than later ;-) ... thanks to such imponderable and childish mind-benders as: how does 'kick the can' ends up in a semiconductor discussion...
