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  1. (*steve*)

    Homemade capacitors, that hold a charge?

    Your statement is 100% correct for all instants lasting a little over a minute. I'm actually pretty impressed by that
  2. (*steve*)

    Homemade capacitors, that hold a charge?

    In addition, the film is a lot thinner than paper so the capacitance of your capacitor should be significantly higher.
  3. (*steve*)

    Resistors, Capacitors, Zener diodes... Why the funny values?

    1) zero is not a value in the E series. But zero ohm resistors are available as are resistors that have values not in any E series. 2) to minimise change, a 1,2,4,8,16... series might be better. But given we have 10 fingers, 1, 2, 5 is a close estimate that repeats each decade. To maintain a...
  4. (*steve*)

    Trumps solar wall, forget politics we should just build the thing

    I generally prefer something useful, required and fit for purpose be built, as opposed to just something.
  5. (*steve*)

    Shake Flashlights power

    Dynamic braking.
  6. (*steve*)

    How ac work in single phase

    Do you know how DC works?
  7. (*steve*)

    Happy 150th Canada

    Important tip Canada: If you're going to put 150 candles on a cake and light them, make sure it's a big cake. Oh, and send me some. Thanks Canada, and you don't look a decade over 100.
  8. (*steve*)

    AOC monitor repair

    Do you have a picture? Knowing what this device looks like and even the surrounding topology may help answer the question.
  9. (*steve*)

    Lithium Ion 18650 cell capacity

    If they want to calculate capacity by effectively "red lining" the battery on both the charge and discharge phase, my recommendation is that you don't want to repeat their tests. Decide on your own charge and discharge limits, test with these, and live with the smaller capacity and longer life...
  10. (*steve*)

    Coil Question

    If you can't identify a difference in behavior between a working unit and your unit then there's not much we can do.
  11. (*steve*)

    Measuring an IC's input resistance

    I believe the offset voltage listed in the application note is the maximum offset of the op amp (although as noted above, other specs say 15mV), i.e. the differential voltage required to make the output 0V. Without seeing the email, I can only suspect what it means, however you typically don't...
  12. (*steve*)

    Coil Question

    Ok, so what should they be doing, and what are they doing?
  13. (*steve*)

    Trumps solar wall, forget politics we should just build the thing

    Those are the easiest things to know.
  14. (*steve*)

    Coil Question

    One option would be to tell us what the thing which uses the coils is, what it is supposed to do, and then how it comes up short with your coils. For example:. The finite improbability generator is supposed to create finite amounts of improbability, but with these coils all I get is average...
  15. (*steve*)

    ADC Hold and Sample

    That's one important one. If you're using atmel chips, check out the Avr127 application note. Even if you're not it still may be helpful.
  16. (*steve*)

    Triac Testing

    Best thing is to test them. An SCR has a diode junction between the gate and cathode. A TRIAC is sort of like a pair of SCRs in antiparallel, but that would mess up the triggering. If you look at their construction they have a pretty weird configuration that effectively places two...
  17. (*steve*)

    Triac Testing

    It's a bit tricky to see in the TRIAC, but in the SCR it is obvious there is a diode junction between the gate and the cathode. The same sort of thing applies for a TRIAC. You should expect a high resistance between the main terminals, not the gate and MT1.
  18. (*steve*)

    Measuring an IC's input resistance

    If the input impedance is asymetrical, you can handle the positive and negative cycles separately. If the resistance is non-linear, you can start with different initial voltages. With really high input impedances, the additional input resistance can cause a significant increase in noise. It...
  19. (*steve*)

    Measuring an IC's input resistance

    I have never read the resistance of a chicken. However for high resistance inputs you could use something like an electrometer to measure the input current. If the current is as high as several pA, a more simple picoammeter may suffice. However these instruments are finicky beasts, and you...
  20. (*steve*)

    ADC Hold and Sample

    No -- not really. Yes, possibly. But it's far better to read the specs of the micro-controller that you're using to make sure. An ATMEGA 328, for example has an input capacitance (14pF from memory) that is allowed to charge for 2 clock cycles (again, from memory) prior to it being read. If...
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