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  1. (*steve*)

    Signal flow fundamentals

    A signal at the input causes things to happen elsewhere in the circuit. This results in something Tha appears to be the same signal appearing elsewhere (as your voice does when speaking on a telephone -- the sound heard is not the same sound you made, it is a copy of I made somewhere else). In...
  2. (*steve*)

    Just saying 'hello'

    Welcome!
  3. (*steve*)

    Capacitor frustration! I'd needed

    I'd say there are some transistors that have failed short circuit. Those devices look like collateral damage.
  4. (*steve*)

    Need an expert to identify this part

    The part labelled NT.... Is a negative temperature coefficient thermistor. The other one is a MOV of some sort. I'd google the part numbers or look them up on digikey. Why do you need to know what they are?
  5. (*steve*)

    Laptop Power Jack

    It looks like all the current is likely to be carried through the plating on that hole. Its a pretty big hole, so its probably OK, but if I were mine I'd do a proper job soldering the top. How good are you at soldering? Also, I said the bottom looks OK, but since the connection doesn't...
  6. (*steve*)

    12v 3amp battery charger lead acid

    Yes, it requires filter caps for this statement to hold true. Its the filling up of the bits between the half waves which causes the issue.
  7. (*steve*)

    sound frequency resulting from coil windings

    What you're saying seems devoid of any meaning I can discern. Perhaps it's the way you're saying it, or perhaps there is something I'm missing, but I'm not getting it.
  8. (*steve*)

    sound frequency resulting from coil windings

    It is known as the "brown note".
  9. (*steve*)

    12v 3amp battery charger lead acid

    40% higher, therefore 30% lower. It's multiplication and division, not addition and subtraction.
  10. (*steve*)

    sound frequency resulting from coil windings

    Well kinda... The speaker coil typically moves within a magnetic field. The coil is connected to the cone and it also "floats" in the magnetic field. The magnet and the cone are not connected (well the kind of are, but by flexible material allowing them to move independently. If you were to...
  11. (*steve*)

    Laptop Power Jack

    Actually, if the problem is a high resistance connection it could also explain the charger running hot. The laptop almost certainly contained a number of switch mode regulators and they will respond to the voltage drop across the faulty joint by demanding more current. It might be a "one...
  12. (*steve*)

    sound frequency resulting from coil windings

    Thanks for the explanation. It tells us more about what you (mis) understand than what you want to do, but that's ok. Making a wire vibrate is *exactly* what a speaker does. It also has a surface (often a paper cone) attached to help make the air vibrate so we can hear it better. Also, a...
  13. (*steve*)

    Connecting Lithium Ion Batteries in Parallel

    There is nothing intrinsically bad about connecting batteries in parallel. However if the state of charge is unequal, the one with the highest voltage will try to charge the one with the lowest voltage. In the best case a small current will for for a short time until the voltages equalise. In...
  14. (*steve*)

    Winco generator not producing electricity

    The "mainframe" may have provided an earth return. If it was connected via metal fasteners, why not try connecting these back to the frame via heavy cable.
  15. (*steve*)

    hi everyone

    And many of us remember prehistory like it was just yesterday.
  16. (*steve*)

    12v 3amp battery charger lead acid

    Imagine you have a 10V RMS AC 100VA transformer. We will assume nice sine waves and that the current drawn is 10A RMS. We know that RMS measurements create an equivalency in the ability to heat something, and thus they allow us to measure power. If we assume that current and voltage are...
  17. (*steve*)

    sound frequency resulting from coil windings

    If you wind a coil loosely, the windings will move in the presence of the magnetic field and buzz in time with it.
  18. (*steve*)

    Power From Sterling Engine

    An MPPT controller ensures that things are operating in the "sweet spot" at all times. Otherwise it's a bit of a lottery and you have to do a lot more work to ensure it reaches equilibrium somewhere near it. The one thing in your favour is the constant (or near constant) heat input. However...
  19. (*steve*)

    Power From Sterling Engine

    If you remove the battery then you need to ensure that your load is compatible with the power being generated. This typically means you need excess power generation capacity. Replacing the batteries with a bank of capacitors and using a zener diode to limit the max voltage is a reasonable...
  20. (*steve*)

    Power From Sterling Engine

    Have it spin a dc motor and use a MPPT type controller to maximise the power. Use it to charge a battery (lithium or lead-acid are the easiest) and use the battery to power a load. The major problems are: 1) ensuring the regulator doesn't consume more power than that being generated. 2)...
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