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  1. BobK

    Driving this MOSFET with PIC

    Highly resistive sounds like skin to me. Are you trying to build a taser? Bob
  2. BobK

    "random" blinking LEDs: purpose-built circuit, or Arduino or =

    Um, why are you using UV LEDs? You know the light they produce is not visible, right? Bob
  3. BobK

    Solar Panel running 2x20m RGB strips

    Just out of curiosity, the solar panels will only produce anything close to their rated output in bright sunlight. Is this when you are planning on running your lighting strips? Bob
  4. BobK

    Computer/electronic integration

    There are inexpensive boards that will plug into a USB port and provide digital and / or analog output and / or inputs. Look up "USB TO GPIO" Bob
  5. BobK

    Reading PIC ports

    A jump table is better than either of the methods discussed in this thread. Bob
  6. BobK

    Base resistor from PIR

    A 2N3904 is rated at 200mA continuous current. You cannot use it to switch 14W at 9V which is 1.5A. Bob
  7. BobK

    PIC12LF1571 PWM Issues

    What have you put in the PR2 register? This register determines how high to count before the counter is reset. The duty cycle can be no higher than the value in the PR2 register, so it sounds like you have put 0x10 in there, which means the highest meaningful duty cycle is 0xF. Bob
  8. BobK

    N Channel JFET Testing in ESR Tester

    Two states away, 5000Km? Here in Massachusetts, 2 states away is about 150Km :) Bob
  9. BobK

    RT8059 step-down DC/DC converter - can't get it to be stable, annyone with experience?

    At 50nA max current into FB, the large resistors should not be a problem. I also don't think layout would cause it to be off by that much. After checking the connections over very carefully, I would start trying to substitute parts, starting with the IC if you have another one. Bob
  10. BobK

    N Channel JFET Testing in ESR Tester

    Mine identifies an MPF102 as a single resistor. Bob
  11. BobK

    LEDs in parallel don't consume sum of individual currents??

    Agree, but try telling that to the makers of cheap Chinese LED flashlights. Bob
  12. BobK

    hydrogen powered electrical motor

    Hydrogen based fuel cells were all the rage as the future for electric cars about a decade ago. Then they discovered just how difficult it is to store enough hydrogen to give you any range. Lithium Ion batteries are far more practical. Bob
  13. BobK

    LEDs in parallel don't consume sum of individual currents??

    You also did not tell us you used different color LEDs! This is a total no-no. Different color LEDs operate at different voltages. If you ever were to parallel LEDs, which you should not, they should be as similar as possible. Bob
  14. BobK

    LEDs in parallel don't consume sum of individual currents??

    You schematics show a very different story than you told in the original post. In the OP, you mentioned putting in parallel LEDs (number not stated) that would individually draw 60mA and getting 22mA, or 36% of the expected current. Your later posting shows two in parallel that draw 16mA...
  15. BobK

    dc to ac calculation

    It is easiest to do it as watts hours. The two batteries have 2 x 6 x 4.5 = 54 W H. Assuming an inverter that is 80% efficient, you would get 43 W H after inverting to AC. Bob
  16. BobK

    LEDs in parallel don't consume sum of individual currents??

    Wow, my gut agrees with Steve's brain! Bob
  17. BobK

    PIC Micro Output I/O

    Connect a 10K resistor from the + to the - terminal of a 1.5V battery. Is the voltage at the - terminal now 1.5V? If not, what is it? Bob
  18. BobK

    LEDs in parallel don't consume sum of individual currents??

    No. I don't believe any of it. With a bench power supply and a circuit requiring only 60mA the voltage is not going to drop enough to lower the current to 22mA. We need a schematic, showing how everything is connected, including the meters. And you need to redo the measurement using two...
  19. BobK

    how to discharge battery

    Depends on how long you want it to take. Use 5Ω and it will not get so hot, but the test will take 10 hours instead of 1. Edited to add: Anything you do to drain the battery in 1 hour is going to produce the same amount of heat, unless it is doing some actual mechanical work, like lifting a...
  20. BobK

    LEDs in parallel don't consume sum of individual currents??

    If your voltage source was perfect, and you measured the current through each LED at the same voltage, then you should get the sum of the currents when you parallel them at that voltage. So you are (theoretically) correct that the result is unexpected. What is your voltage source? I suspect...
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