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  1. BobK

    Is there any different using two power supply?

    Is there is particular reason why you must run the micro at 5V? Modern micros will run at 3.7V, in fact most of the newest ones will not run at 5V. Bob
  2. BobK

    understanding the pic16f627a

    Yes. Bob
  3. BobK

    understanding the pic16f627a

    You need to include #include <p16F627A.inc> And the symbols will be defined. bob
  4. BobK

    Electric Motor to multiple PMA

    Sure you will, just like all the others. Do you want to know why it won't work, or would you rather waste many months and dollars, never quite convincing yourself that it will not work? Bob
  5. BobK

    Portable Mobile Phone charger

    It would work, but it will require about 3 9V batteries (the small rectangular ones) to charge your phone once. Bob
  6. BobK

    Electric Motor to multiple PMA

    What a brilliant idea! I wonder why no one thought of it before! Why are we using all that gas and electricity, when such a simple solution will produce all the power we want for free! What you are describing is a perpetual motion machine. They are not possible. Many have tried over the...
  7. BobK

    Convert DC to AC Circuit [Required] :)

    That is called an oscillator if it is low power and an inverter if it is high power. Can you give us more specifics as to the DC input and the AC output voltage / power requirements? Bob
  8. BobK

    solar

    Sorry, my math was wrong, i missed the 2 hours. You are correct, it is 20Ah. Bob
  9. BobK

    solar

    For a 12V battery: x Watt Hours = x / 12 Amp Hours. If you charge a 12V battery with 120W for 2 Hours you will add 10Ah to it, in theory. Of course the efficiency will be less than100% so, probably about 7Ah. Bob
  10. BobK

    Op Amp Substitute

    Microchip makes a good line of 5V single supply opamps in DIP packages. Check the gain bandwith though, because they come in a wide range. Here is a typical one with all the characteristics you asked for and 10MHz GBP. http://ww1.microchip.com/downloads/en/DeviceDoc/21812e.pdf Bob
  11. BobK

    How to mesure amps at a high sample rate?

    In my simulation, the base goes to -2.4V. Is that bad? I see nothing in the datasheet about reverse voltage on BE. Bob
  12. BobK

    multiplexing using assembly

    Yep. 0 xor 0 = 0 1 xor 1 = 0 0 xor 1 = 1 1 xor 0 = 1 So when you xor the same number you get all zeros as a result. bob
  13. BobK

    How to mesure amps at a high sample rate?

    Here is the classic Joule Thief in LTSPICE. The graph is the voltage across the LED. There is no capacitor. It works by having the current buildup in the coil in the collector turn off the base thorugh the coupled coil, to form a blocking oscillator. It is indeed a very simple...
  14. BobK

    555 TIMER - Trigger Pin 2 Voltage??

    Any voltage over 1/3 V+ will trigger it. This includes V+. Bob
  15. BobK

    Another Joule Thief Thread

    Uh, try 6000000 meters in wavelength, only off by about 9 orders of magnitude... bob
  16. BobK

    Pink noise generator circuit mod

  17. BobK

    multiplexing using assembly

    Say you are incrementing the number 15. Once you have incremented the 5 you are done, you don't have to increment the 1. That is why it skips to the end of the subroutine when the result of incrementing the ones is not 10. Now, if it is 19, after you increment the 9, you get 10 and you want...
  18. BobK

    spring/plate reverb

    opamps are typically not capable of driving a speaker. Why not use an audio amp as I susggested way back? Bob
  19. BobK

    Help with Atmega328 project

    You TIP120 is probably losing you 2V. Maybe you would be better off to use the 14V input rather than regulating it down to 12V. A MOSFET would have been a better choice. Bob
  20. BobK

    4049 hex inverting ic

    Did you see a bright flash the first time you connected it, then no light thereafter? You need a resistor in series with each LED. Read this: https://www.electronicspoint.com/got-question-driving-leds-another-work-progress-t228474.html Bob
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