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  1. BobK

    Transistors amplification

    I do not see it as contradictory. The OP seems to think you can take a transistor and a 5A supply, and get a 10A supply from it. My point is that the output current comes from a power source, not from the input current "amplified". Perhaps you would like to phrase it better? (I have added...
  2. BobK

    1/4 inch mono jack 3 pins

    Or a stereo jack. Bob
  3. BobK

    Transistors amplification

    All of them. :p Bob
  4. BobK

    Transistors amplification

    What a transistor does is controls a large current based on a small current. It does not create current, the large current must come from a power source. There are circuits that can double the input current, but it is always at the expense of halving the output voltage. The power, which is...
  5. BobK

    Sherwood AM 7040

    Get a ground loop isolator to plug between the CD player and the amp. Something like this Bob
  6. BobK

    Woo-Woo MOSFET switch question

    Depending on the specific MOSFET, the gate must be anywhere from about 2V to 10V above the source. This is for an N-channel device. 5V might or might not be enough, you need a logic level MOSFET to turn on at 5V. Bob
  7. BobK

    theories that partake to rechargeable fan construction

    I think "theories" might not be the best translation. Perhaps "principles" would be more what is meant? Think about what parts you will need and what attributes they will have that are important in choosing them. Bob
  8. BobK

    Newbie 12v meltdown, please help.

    Amps are something a battery can supply. It only supplies them if what is connected needs them. You can always use a power supply with a higher current rating than the device requires, but not the reverse. The the voltage must actually match the required voltage (or be very close.) I agree...
  9. BobK

    Can Crusher - High School Physics Porject

    Very dangerous if you touch the contacts. Bob
  10. BobK

    Can Crusher - High School Physics Porject

    Yes, that has the coolness factor required to keep 18 year olds interested! And it demonstrates some real physics. Bob
  11. BobK

    Making a battery to charge my laptop on the road

    Apple, Samsung and Boeing are just a few of the companies that have built Lithium Ion chargers that cause the batteries to explode. And you, who admits he doesn't know how current works, want to build one? If you build your own battery pack and take it on a plane with you, please inform me of...
  12. BobK

    PiC A/D loading signal

    The PIC is not loading it, it is the voltage divider. Increasing the resistors to 100K and 200K will help and should not effect the PICs ability to read the digital signal. Bob
  13. BobK

    Sherwood AM 7040

    Could be a ground loop. Are the amp and CD player plugged into different outlets? Bob
  14. BobK

    Questions about LM386 Audio Amplifier.

    Audio comes to mind as the correct category. Homework help is a special forum in which we do not give direct answers, since that would be cheating on your homework. Bob
  15. BobK

    Current source for a Capacimeter

    The capacity of a battery varies with the discharge rate, so you should allow for a variable current. Also, what are you going to ise for the end criterion? Bob
  16. BobK

    Questions about LM386 Audio Amplifier.

    This does not sound like a homework question. If it is, what is the actual assignment? Bob
  17. BobK

    Help with slowing down and reducing the noise on a shaded pole 230VAC fan motor

    Yes, I understand that. My warning is for when he puts that one back in the fan he borrowed it from and buys a capacitor for this fan. bob
  18. BobK

    Help with slowing down and reducing the noise on a shaded pole 230VAC fan motor

    More, accurately, the capacitor MUST be non-polarized. Do not try to use a polarized electrolytic capacitor. Bob
  19. BobK

    Handy timer module

    Now, if only we could interpret this means: The chart they have for resistance vs, delay (which is dependent on supply voltage!) shows it going only from about 5 seconds to about 7000 seconds, which is a far cry from 1000h. Perhaps chaining them for the longer delays? It looks to be an RC...
  20. BobK

    Kw HR ESTIMATE TO COOL A CHURCH 132'l x 60'Wx 55'h - 70 DEGREES IS TARGET -

    Zero, if it never gets above 50 degrees outside. Seriously, there are so many variables that would effect this, that I think you would need an HVAC expert to evaluate the site. Bob
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