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  1. BobK

    Embedded Software Architecture

    It is not clear what you mean by this. Each project has it's own software architecture. You mention critical sections, so this implies that you will be running multiple threads, probably with pre-emptive scheduling. Are you using a specific RTOS for this? Bob
  2. BobK

    Modified Sine Wave Inverter

    Do you have a load on the secondary? If not, try putting an appropriate load in the way of a small light bulb. Bob
  3. BobK

    analog cpu and multiplexing with discrete components

    Yes, but could it run a web browser? Most likely, what you saw was a very simple analog computer that could solve 1 particular equation, possibly with the speed of an early 16-bit computer. Bob
  4. BobK

    Combining notebook (laptop) chargers for more POWER ?

    Yes, like that. Except neutral, not ground on the AC side. Bob
  5. BobK

    AC Voltage Amplifier

    Well, the working circuit was not a power amplifier. This one is. But a bit expensive as you note. Bob
  6. BobK

    How to control 700 solenoids?

    If you are going to power this with a 360W power supply, I hope your solenoids use less than 1/2 W each. Bob
  7. BobK

    AC Voltage Amplifier

    That is a much better circuit. It is a standard common emitter amplifier. Common base is normally used for current amplification with very low input and output impedance. If LTSPICE shows it working it is likely to work reasonably well when built. Note that the output impedance is going to be...
  8. BobK

    LED power source

    The 74595 shift register lets you shift in all the bits then enable them all at once. For 300 LEDs, running the shift clock 300KHz (easy) you could change all the LEDs 1000 times per second. Bob
  9. BobK

    computer fans - Very basic question from a beginner...!

    The current capability does not matter as long as it is greater that needed by the device being powered. An electronic device will draw only the current it needs when provided the correct voltage. Bob
  10. BobK

    Trying to find type/name/replacement cord

    12V 0.95A and 70W? Bob
  11. BobK

    Controller boards for multiple relays

    If it isn't top secret, what is the application? Bob
  12. BobK

    Microcontroller controlled by pushbutton for LED flashlight

    Nice job. You could use pogo pins for programming. They are spring loaded, which is necessary because you will never get 5 pins to connect reliably without springs. I would put a hole in the middle of the programming pads to keep the pins in position. You could make a matching board with...
  13. BobK

    LEDs in series?

    Good to hear you got it working. You can make 2 strings of 3 each and have a separate LM317 regulating the current to each of the two strings. Bob
  14. BobK

    LEDs in series?

    Yep, that is how you put them in series. Bob
  15. BobK

    5v linear voltage regulator design problem.

    Your friend is correct about switching regulators at low currents, they lose efficiency when run well below their rated current. But we are talking well under 1A here. Bob
  16. BobK

    fried L298N, stepper motor fun...

    Your problem with running it at 5V is that the L298 is dropping about 2V, which gives you 3V left for the motor. A MOSFET bridge would solve this problem. I have some of these: http://www.diodes.com/datasheets/DMG6602SVT.pdf Which gives you a P channel and N channel in one package. They...
  17. BobK

    LEDs in series?

    That article has two diagrams, one series and one parallel. What you have described is parallel. All of the + leads from the LED are going to the power + and all of the minus leads are going to the power -, right? Bob
  18. BobK

    E series

    Well, that is the E12 series, what about E96? :) Bob
  19. BobK

    Capacitors dielectric

    Current flows while a capacitor is charging or discharging. That is why you see the bulb light up. Current does not flow through a capacitor, it flows into the capacitor on one side and out of the capacitor on the other side until the capacitor is charged to the voltage that is driving it...
  20. BobK

    LEDs in series?

    Perhaps this will help: http://www.allaboutcircuits.com/vol_1/chpt_5/1.html Bob
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