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  1. CircutScoper

    Super Capacitator Charging

    No. A 12V supply, even though limited to 12V/24ohm=0.5A, will try (however slowly) to charge your 5V supercap to 12V, which will (eventually) overvoltage and probably destroy the cap.
  2. CircutScoper

    Force Feedback for i.e. Logitech Yoke

    Ditto. Better (and simpler and probably cheaper) than a stepper would be a brushed DC motor, in which both the magnitude and direction of torque are determined by the amplitude and polarity of applied armature current. Then a screw & nut assembly could convert torque from the armature into...
  3. CircutScoper

    Transistor as a switch

    I think now you're conflating eponyms (Euclidan, Newtonian, Darlington, et al) with trademarks (Visegrip, Xerox, etc,)
  4. CircutScoper

    Transistor as a switch

    What about fig.s 8 and 9?
  5. CircutScoper

    Transistor as a switch

    Excellent. Now, if you'll be so kind as to scan down to "Packaging" in that same Wiki article, you'll find... Packaging "Darlington pairs are available as integrated packages..."
  6. CircutScoper

    Transistor as a switch

    Agreed. Which, of course, is what a Darlington is not.
  7. CircutScoper

    Transistor as a switch

    True. It's a good way to lose your favorite pet rock.
  8. CircutScoper

    Transistor as a switch

    Doesn't that kind of depend on what they take with them when they go?
  9. CircutScoper

    Transistor as a switch

    The 2N3055 is a silicon NPN power transistor intended for general purpose applications. It was introduced in the early 1960s by RCA using a hometaxial power transistor process, transitioned to an epitaxial base in the mid-1970s https://en.wikipedia.org/wiki/2N3055#:~:text=The 2N3055 is a...
  10. CircutScoper

    Light bulbs as dummy load for Stereo ?

    True -- with clusters! Less because of the lower temperature, and less again because heating elements are typically made from wire (e.g. nichrome) with a much lower tempco (e.g., ppm/C vs ppk/C) than tungsten.
  11. CircutScoper

    Light bulbs as dummy load for Stereo ?

    Probably more like 6 Ohms. A bulb filament when ON runs around 2000C, so a 0.5%/C tungsten tempco produces a 2000 x 0.005 = 10:1 increase in resistance hot vs cold.
  12. CircutScoper

    Please help a lay person with some repair questions

    Another random question: Is it possible the grandkidling engaged in a contest of strength with the remote control cord -- and won? A replacement is available at a not-completely-absurd-price. It might be a worthwhile experiment to invest in...
  13. CircutScoper

    Please help a lay person with some repair questions

    Well, I have grandsons of roughly that age too, and their mission in life seems to be to get stuff greasy and sticky and to mix poorly with electronics.
  14. CircutScoper

    Transistor as a switch

    Looking back over the content of this thread, I'd say it worked!
  15. CircutScoper

    Please help a lay person with some repair questions

    A question: Is the control panel sticky or greasy? The first thing I'd check for is contamination -- something spilled, wiped, sneezed, or drooled onto the control buttons. If that is the problem, it should be easy to disassemble the unit and clean it up with alcohol and distilled water...
  16. CircutScoper

    Transistor as a switch

    Interesting to be reminded that FET "saturation" is essentially the complete opposite of bipolar "saturation." For a "saturated" field effect transistor, output current remains (approximately) constant, independent of output voltage. For a "saturated" bipolar transistor, output voltage remains...
  17. CircutScoper

    Transistor as a switch

    Why would a darlington be a hybrid circuit instead of an IC?
  18. CircutScoper

    Transistor as a switch

    Truth is, I've always studiously avoided the '3055 in any application involving more than ~1A of collector current. Much higher than that and its beta goes to pot even before its saturation voltages do. For higher currents there are better choices and have been for decades.
  19. CircutScoper

    Transistor as a switch

    Sorry. That's not true. For proof, note figure 7 ("ON voltages") in this datasheet. https://www.onsemi.com/pdf/datasheet/2n3055-d.pdf
  20. CircutScoper

    Can mosfet driver supply continuous current of 2Amps?

    Your circuit would probably work better if R63 and R65 are replaced with direct connections, thus insuring a full 5V drive for the MOSFET gates..
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