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flippityflop

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  1. I appreciate your work

  2. so it's Ve = Vc - Vbe? ok... i missed that from just reading from wikipedia... i read the voltage on the load is *mostly* is constant for most of the operating current range... then again the examples from wikipedia has the load on the collector side... collector side, then...
  3. well, emitter in saturations is still slightly bit higher... (Ie_sat = Ib_sat * (1 + hfe))
  4. answering my own question again: it just struck me, but maybe the capacitor was not charging not because of properties of currents in collector and emitter for any NPN, but because i've been thinking in terms of conventional current... Let: Q be a sub-circuit of an avalanching transistor and capacitor in parallel. in my case, the avalanching transistor is 2N2222; the "generic NPN" is not the 2N2222 mentioned. whenever Q was in the emitter side of the generic NPN, the negative terminal of the Q's capacitor is already in the highest negative charge. the momentary opening of the gener
  5. i'll solve the specific circuit problem on my own... although, i would like an answer on the first question... when switching, is it better to go with the emitter on NPNs and the collector on PNPs?? do their electrical characteristics differ more than slightly higher currents?
  6. i'm asking as i've been working on a design that to my understanding should've worked. i have a generic NPN restoring the supply voltage and feeding it's emitter output to a 2N2222 parallel to a charging capacitor for a delayed avalanche. somehow the avalanching only works when i swap the 2N2222 + charging capacitor sub-circuit to the collector side. it surprised me as when it was connected to emitter, it was also directly connected to ground. and when it was on the the collector side it was directly connected to the supply. so it was not isolated and would be biased to a common ground. altho
  7. alright, continuing the series... another question i would like to as is on NPN BJTs, would it be better to put the load on the collector side or the emitter side?? in schematics, i almost always see it on the collector side (Ic = hfe * Ib), but the emitter side also works and when doing plain switching (in saturation) the emitter side works at least as well (Ie = Ib * (1 + hfe))... so would there be any difference? the same with PNPs, when it comes to switching, would the collector side (Ic = Ib * (1 + hfe)) work better than the emitter?
  8. i need to know what is the lowest current that is reliable for cases such as: a.) charging a capacitor b.) when the current is being read by an instrument such as an ammeter c.) logic signals what i mean is that even outside normal conditions -- exposed to hot summers and cold winters, being touched by bare hands when testing, or when it's humid, etc -- what are the minimum low currents that will cover a, b, c above?
  9. are these NPN BJTs: http://pdf1.alldatasheet.com/datasheet-pdf/view/17918/PHILIPS/MMBT2222A.html the same as those 2N2222 that has been around for since forever? can i trust that the reverse active and avalanche breakdown profiles are the same??
  10. ok i actually just realized the flaw after i last posted. i thought of mentioning it, but i thought it will have you guys think that i am trolling. (i actually just checked again for additional posts from you guys) yes, hero999 there needs to be a common ground here for this to be a universally applicable (aside from the aforementioned caveat that you have to balance the R1 and R2). to see why, we need to visit what was posted in this thread (hence my fear of this being seen as trolling): http://www.electronics-lab.com/forum/index.php?topic=39704.0 basically, V1 and V2 are just voltage dro
  11. i was wondering why is it, for just half duplex systems, don't we have a dedicated transceiver and a dedicated transmitter antenna. ok, just hear me out... assuming we are using grounded monopoles, we can have a resonator connected to a diode whose anode is connected to the transmitting antenna, and have a receiving second antenna connected to the cathode of another diode then going to the resonator. the transmitting and receiving antennas would also be made of different materials that are nonreciprocal. ferrites that are biased to transmitting and receiving (higher gains). since they're h
  12. you know what i'm talkin' about... anyways, just in case somebody stumbles upon this simple thread in the future, i'll attach a more concise diagram:
  13. also, why i am convinced that sometimes it might be helpful to consider "pulls" is that i see a lot of voltage supplies apparently provides negative voltages.
  14. ok, i guess i lose here... in all cases "conventional current" and the idea of 0V grounding that comes with it abstracts all cases when it comes to passive components. in active components as long as it is only immediately in series with a passive component, then it *should be safe*. if 2 or more active components are in series, then i'd still raise questions if it could work. ok, look at the attached diagram and apply conventional current and see if we can make it all work. suppose the 2 identical avalanche diodes in series with a active component "Q". we also define an "ambient" voltage
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