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    Antenna Design to Capture Atmospheric E-field Gradient

    Effective input impedance of an electroscope might be a little higher than even a good dvm.
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    npn question

    GPIO pins, as gates, usually have a specified high and low voltage threshold, sometimes expressed as a proportion of the supply. Example; for I2C pins 0.3 & 0.7 of the supply. That is anything less than 0.3 of the suipply will be seen as a low, 0. anything greater than 0.7 of the supply will be...
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    Antenna Design to Capture Atmospheric E-field Gradient

    Ok, on principle, I object to the teaser image of holding up a glowing incandescent bulb. Electroscope, ok, corona motor, ok, At a risk of extra o3, much larger corona motors are possible, but never seen one with any significant torque to speak of. . If you just want to measure the voltage, I...
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    Antenna Design to Capture Atmospheric E-field Gradient

    It's essentially DC. Not sure what AC you want to block. I'd suspect that any AC signals, right up to the point htat you get hit by lightning, may be too small to bother about. What sort of thing are you doing the measuring with? It will need a reasonable input impedance.sensitive, sure, ok, I...
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    A Phoney Question

    Used to be able to buy magnetic pickups, often with ampllifiers, for analogue phones that picked up the audio directly, for recording & such. Not sure whether such are still available, but might be worth a search. Used to matter where you put them, so if you find one, move it over the phone to...
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    Radio

    I took it to be these immediately. They often form part of resonnant circuits in the radio, to allow selection of bands, to filter out things that are not in the intended band. As you can see form the ciruit posted above, there's a bit involved to use them well. You can use them to make simple...
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    Radio

    I feel so old. :)
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    Help Needed To Build A Device

    Not quite sure where the magnetic sheet fits in. . Detecting a specific sound, well one that sounds "specific" to a human with years of training, can be more difficult than some think. Might also need a bit of computational power. MIght want to google this part a little. . Not sure where you go...
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    How do you get homework help when you reach master's level of very higher level of education?

    I guess just echoing what's been said above: for any discipline, at say Master's level, there's actually thousands of people who have done this. Many of them, and other, sometimes without formal qualification, yet actual academic-level understanding, particularly in these areas of technology are...
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    2N2222 questions

    No criticism intended. I'll leave it in your capable hands. :)
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    2N2222 questions

    Liked this ... But, out of interest, what makes you think 180 Ohms is the correct value? (Probably right, just interested in how it came about) If this was to set some current, then maybe you already know the current per LED (and resistor)? . The analysis above still applies, but that current...
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    Nano circuits

    Believe what you want to believe. It's nothing but organic-looking stuff after some liquid evaporates.
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    Capacitor size

    You can google and look for something to check what I say, as you wish. . Of loads that need power, such as motors, inductive loads and heaters, heaters are the simplest; they look resistors. No substantial phase shifts. Motors are a bit more complicated. They have inductors and the load...
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    Capacitor size

    The energy delivered to a heater is basically all turned into heat. Smoothing the current will not save any energy. . If you want to get away from a perception pulses of hot & cooler, probbably better yo look to a PWM controller with a faster cycle time. . Again, if you want to experiment with a...
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    Capacitor size

    To answer your question: Likely huge, also likely not a good idea without circuit changes. Take a look at https://www.electronics-tutorials.ws/rc/rc_1.html or similar. Google capacitor charging or similar. But, other questions are probably better asked first. Why? Often heaters have...
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    Custom Dog underground shock collar

    In some systems there is an audible training warning that sounds before the point that any shock is administered. The association rapidly becomes that the activity should stop on the warning without the shock being administered. . Pavlov style, I too would tend preferntialy towards positiive...
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    Portable Computers

    Confirm GPS is receive only & only location & time signals. NFC is powered from the reader, the other end, so won't come up unless very close, as it's designed. If new enough to have UWB, it'll act rather like bluetooth. .
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    Portable Computers

    Is NFC enabled in airplane mode? Just interested. Maybe NFC is not a concern to you? If recent, UWB maybe also.
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    Portable Computers

    Remove the probably surface mount antenna? (and match output to load?) Some may have more than one. Do you want to disable bluetooth and Wifi as well?
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    PWM shielding

    Frequency? Voltage? Current? Distance to possibly affected circuits? What is being shielded from it? In short
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