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  1. Alec_t

    Electromagnetic emission...

    A good quality dynamic mic is unlikely to be sensitive to external magnetic fields, since its moving coil will be buried between concentric magnet poles and thus screened.
  2. Alec_t

    Trouble with 555 flyback driver circuit

    For actual grounding you might want to read up about "star grounds"; the idea being to have a single ground point from which connections-paths-to-ground radiate, so that heavy power currents are kept separate from small signal currents in those paths.
  3. Alec_t

    Trouble with 555 flyback driver circuit

    Yes. Ground symbols are for convenience and tidiness, so that you don't have to draw straggly wires snaking all over the place in the schematic. Your drawing looks ok.
  4. Alec_t

    Trouble with 555 flyback driver circuit

    I think this is what the author meant :-
  5. Alec_t

    Non contact AC voltage tester

    AC-DC adapters are not usually well screened, so stray radiated EM fields are present which can be picked up by your body and by nearby wires, such as the one you are holding in the pic.
  6. Alec_t

    New (NOS) switches with contact problems -how to fix?

    The internal contacts have likely oxidised/tarnished. Any chance you could squirt a drop of switch-cleaner inside?
  7. Alec_t

    New Product Prototype

    Perhaps the receiver has some sort of AGC which is cutting in and out? Just a guess.
  8. Alec_t

    Introducing myself...

    Welcome to EP, Jim.
  9. Alec_t

    I need a critical help in designing a magic toy

    Rather than use a radio link, a magnet in the wand and a Hall sensor in the ball might be simpler.
  10. Alec_t

    AC circuit voltage can be described using a sine wave with the equation??

    v = amplitude x sin((2 x pi x frequency x time) + phase). Compare that equation with the one you have been given. Welcome to EP.
  11. Alec_t

    translating schematic for device variant

    27R is way too low. Did you mean 27k? Why did you up the cap value to 10uF?
  12. Alec_t

    New Product Prototype

    About 6 times as long, in theory. But if you don't have room for a switch, how will you accommodate the bigger battery?
  13. Alec_t

    Electric Motor high pitch sound

    Dry bearings? Try cleaning the motor and lubricating the shaft bearings.
  14. Alec_t

    24VAC half bridge rectified = xx DC???

    Although the average voltage of half-wave rectified 24VAC is around 10VDC, the voltage on the smoothing cap will be close to the peak voltage, namely around 33VDC as Steve said.
  15. Alec_t

    How to connect op amps in parallel

    What opamp are you using to drive a 120V power line?
  16. Alec_t

    12V to 33V Converter

    The 2N3906 is good for 200mA max, so you'd need a higher rated transistor.
  17. Alec_t

    New Product Prototype

    Do you have room for a 2.5mm switched socket like one of these?
  18. Alec_t

    Braun 6520 shaver battery replacement

    Can you upload the pics here, so that any links don't get broken?
  19. Alec_t

    Need relay that operates with 3.8 VDC input.

    What do you want to control with the relay? Have you considered using a solid state switch instead of the relay?
  20. Alec_t

    How To Prevent Short Circuit With A Simple Wire From One Outlet Prong To The Other

    Colloquially, a 'short circuit' is just a current path able to cause damage or blow a fuse. Theoretically, it is a current path of zero resistance. So what do you understand by the term 'short circuit' ?
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