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  1. OBW0549

    Accelerometers for accurately indicating position?

    In principal, yes; it's done by processing the accelerometer's output through an integrator to obtain a signal proportional to velocity, and then passing that signal into another integrator to obtain a signal proportional to displacement. In practice, accuracy and drift with time are major...
  2. OBW0549

    Datasheets moving about... Grrrr

    "Grrrr" is right-- and it's not just NatSemi but Linear Technology as well, ever since their acquisition by Analog Devices. All the excellent, old application notes are getting hard to find. At one time I was considering abandoning my long-time habit of downloading data sheets and app notes to...
  3. OBW0549

    dangling emitter circuit?

    Not a damn thing, other than taking up space. I'd be a bit leery of the digital circuits, as well.
  4. OBW0549

    Normal resistors for High Voltage application

    Absolutely not.
  5. OBW0549

    Improve Biometric Lock

    No. It's fine, just the way it is.
  6. OBW0549

    Normal resistors for High Voltage application

    "Thorough" sounds better and is more accurate, IMO. I reserve "pedantic" for those exhibiting a tendency toward out-of-control, pointless, compulsive, combative nit-picking. At one time I thought of doing much the same thing regarding operational amplifiers and comparators, but in the end...
  7. OBW0549

    Normal resistors for High Voltage application

    Smoke. Fire. Explosion. Toxic fumes. The neighborhood burns down. Electrical shock, and possibly other things too horrible to contemplate. Bad move. As has already been noted, current doesn't "want" to do ANYTHING. Current flows according to the laws of physics, period. Also noted, is...
  8. OBW0549

    Beeping from disconnected system

    Ummm... what "system" are you talking about? Could you be a bit more specific?
  9. OBW0549

    INDIA+ POWER GRID

    He's tried electro-tech-online, too. Was a major annoyance there for a while, but they eventually got rid of him (I think). As for why he does what he does, I think you'd need to ask a psychiatrist for that answer; certainly, there's some major dysfunction going on.
  10. OBW0549

    INDIA+ POWER GRID

    The same thing has been happening over on AAC; RK keeps re-registering under new user names, posting the same kind of inane nonsense, getting banned or having his threads closed or deleted, and so forth, several times a week. And it's been going on for months. Nothing seems to deter the little...
  11. OBW0549

    What makes a successful engineer?

    Never, not even once in my 40+ years as a design engineer. Competent people get promoted, slackers get passed by. And sheer idiots just get fired.
  12. OBW0549

    What makes a successful engineer?

    Intelligence, a disciplined mind, technical knowledge, attention to detail, an ability to communicate effectively both verbally and in writing, and a LOT of hard work. Based on your past posts, I know you won't like this-- but you do also need to be able to solder. "Can" is not the same as...
  13. OBW0549

    Can be TL494CN used as op-amp?

    No.
  14. OBW0549

    Op amp problem ua741

    Ah, so that's where he got the idea that the LM318 operates with rail-to-rail inputs. Failure to understand the difference between "absolute maximum ratings" and "operational limits" (or "electrical characteristics") seems to be a common thing-- though not as common as failure to read the data...
  15. OBW0549

    Op amp problem ua741

    Where? Where in that data sheet do you see any such guarantee? In fact, the Input Voltage Range and Output Voltage Swing specs listed in the Electrical Characteristics section of the data sheet make it crystal-clear that neither the LM318's inputs nor its output operate rail-to-rail:
  16. OBW0549

    Interfacing a NTC thermistor to a PIC

    No, it cannot. You can measure temperature deviations from some reference temperature, but you cannot directly measure temperature itself because at any particular forward current and temperature, the forward voltage drop will differ from one diode to the next. Moreover, that 2 mV/C is only...
  17. OBW0549

    Interfacing a NTC thermistor to a PIC

    True. It's also possible, by adding a large-ish resistor between the op amp output and its non-inverting input, to correct for the slight nonlinearity that results from feeding the RTD from a resistor instead of a constant-current source. With a small tweak, that same resistor can also cancel...
  18. OBW0549

    Interfacing a NTC thermistor to a PIC

    Yes, they're a bit more expensive-- but a lot less trouble to work with because they're much more linear. A diode (or a transistor with the base shorted to the collector) can be used, but the problem is the extremely large variation in forward voltage from unit to unit. Unlike RTDs and...
  19. OBW0549

    Interfacing a NTC thermistor to a PIC

    I agree; for the temperature range you're wanting to measure over, using a platinum RTD would be a much better choice, as it wouldn't require a lot of math to linearize it. The circuit doesn't have to be very complex; here's a very simple design I used on one project to interface a 1000Ω RTD to...
  20. OBW0549

    Electronic circuits work in mysterious ways?

    No, trial and error had little or nothing to do with the development of these circuits; they were created through a deliberate process by people who understood the components, their properties, and the mathematics involved in describing their operation. Most of that knowledge has been around...
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