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  1. BobK

    Help me !

    I am assuming the module uses this chip. You are misreading it. The supply voltage for the chip is listed at 4.3V max. It is intended to be powered by a lithium Ion battery and even has the charging circuitry for it built in. Bob
  2. BobK

    Looking for variable frequency transducers or mini speakers

    That would be called a tweeter. Bob
  3. BobK

    Blown multimeter fuse again - Doh!

    Perhaps the pain level needs to be higher. One trial did teach me not to reach for the soldering iron without looking up from my work. Bob
  4. BobK

    Getting Signal Voltage From Source Power

    What do you mean? He did electronics and he has the smoke to prove it! Bob
  5. BobK

    Why I don't like wall warts

    Tell us exactly how you did this measurement. Please say it is something other than "I set my multimeter to the 10A range and connected the probes to the wall wart." Bob
  6. BobK

    Circuit Element for variable current control

    My guess is an HHO generator. The people who promote this fantasy are often confused about the relationsip of voltage, current, and power. Bob
  7. BobK

    3D Printer Thread

    I asked for one from Santa Clause last year, but then I failed to complete my part by researching which one to get. So Santa (AKA the lovely wife Morticia,) did not bring me one. Maybe this year. Bob
  8. BobK

    Blown multimeter fuse again - Doh!

    That is my problem as well. Bob
  9. BobK

    Circuit Element for variable current control

    You will not tell us what the voltages are, ypu will not tell us what the current is. You are cagey about this voltage source that deteriorates over time. You will not tell us what the load is. How do you expect us to help you? Bob
  10. BobK

    Circuit Element for variable current control

    It would clarify things if you would tell us what you are trying to do instead of how you think it should be done. What are the two source of "current" are they actually current sources or are they voltage sources? (A voltage source tries to maintain it's voltage independent of the load, a...
  11. BobK

    Starting with electronics

    If you want to do that project, and you are a beginner, I would recommend Arduino. It is a programmable microcontroller that is intended to support hobbyists, rather than serious electronics engineers. But, you won't learn much about electronics with that project, you will learn about...
  12. BobK

    8x32 LED Panel (WS2812B) Power Requirements

    Here is a screen shot from my scope measuring the voltage across a 1Ω resistor in line with the battery. It is running a 60 LED strip. As you can see, the current varies between 200 and 400 mA with a period of about 2.5mS. All of the LEDS on the strip are on with different colors of the...
  13. BobK

    And the Relay is Called ...

    Nice image of a soldering iron as a magic wand. Harry Potter's got nothing on us. Bob
  14. BobK

    Why do they print brown letters on black chip packages?

    Funny how I never noticed that when I was twenty. My pet peeve is audio components with dark gray labels on black. Made worse by the fact that I am trying to read them in a dakened media room. Bob
  15. BobK

    High Low logic

    OK "feedback loop closed" sounded like just the connection to me, when you meant the dynamic behavior. Bob
  16. BobK

    Need help on circuit.

    The problem is your 100K gate resistor. This slows the turn on and turn off time , keeping the MOSFET half on much of the time, A good value for a gate resistor is 10Ω. Bob
  17. BobK

    High Low logic

    No it won't. The voltage on the pin is set by a voltage divider from the output. If the output is below the regulated voltage, the adj pin will be below 1.22V by the same ratio. Bob
  18. BobK

    8x32 LED Panel (WS2812B) Power Requirements

    I have strips, they will work the same way, since it is the same chip WS2812B. I am running a strip of 60 off a tiny Li ion battery, using max 100 of 255 which is plenty bright indoors, and the typical current, measured with multimeter is 300-400mA. Bob
  19. BobK

    8x32 LED Panel (WS2812B) Power Requirements

    Good question. There is nothing to syncronize the LEDs, so it is likely they will have random phases, and with that many , should average out. I might try an experiment later to monitor the current with my scope. Bob
  20. BobK

    Oscillator

    Two lead (not leg) ones are not oscillators, they are crystals, which require additional circuitry to make an oscillator. Bob
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