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  1. BobK

    Solar cell, photoresistor and motor -- need help

    Here is a starting point for you. http://en.wikipedia.org/wiki/Solar_tracker Bob
  2. BobK

    Fast Counter Design

    Don't know whether this would work or not, but I think it might be worth trying. I am more familiar with PIC, so I am not sure you could do the same with an Arduino. The Arduino ADC certainly has a sample and hold circuit. So why not use it to accumulate the peak? Just use a long sample...
  3. BobK

    Solar cell, photoresistor and motor -- need help

    Using a photoresistor (or any resistor) to control the current to a motor is not a good idea. Tell us what you are trying to accompish and we can probably give you some better ideas. Bob
  4. BobK

    Need Proper Schottky Diode of 100 Watt & operating frequency of 10KHz to 50KHz

    The power dissapated by a diode (or a resistor) is the voltage across it multiplied by the current through it. The voltage across the diode is not 100V it is about .3 volts as Harald has already said. If you force the voltage across any diode to 100V you will produce smoke. Bob
  5. BobK

    How do drive a power mosfet gate

    I have used a single transistor and a resistor in cases where the switching is not very fast: 10KHz or less. For faster switching, you would need a level shifter first, then a complementary pair of transistors. And typical BJT transistors like your 2n2222 would not be fast enough. This is...
  6. BobK

    Replicating exact battery voltage and current for devices

    Electronic devices do not generally draw a constant current. Think of an audio amplifier. If you turn up the volume, it is going to draw more current. In fact, it is going to draw a variable amount of current over each cycle of the output signal. So you cannot reduce the voltage to it by...
  7. BobK

    Stripboard

    Yep. I use a drill bit that was intended for a drill driver, with the large hex shape on the end. This is easy to twist by hand. Bob
  8. BobK

    Stripboard

    I use a 1/8 in drill bit, twisting it by hand in a hole until the strip is cut. There is also a tool you can get that does it the same way. Bob
  9. BobK

    Rodin Coils

    Yes, free energy devices do not work. Bob
  10. BobK

    Schematic to reality conversion

    Not to mention that fact that, if what you are going to plug in is a guitar, it makes absolutely no difference which lead is connected to ground. A guitar pickup is nothing but a coil of wire and nether side is connected to any ground. And if the amp is battery powered, it is also floaing...
  11. BobK

    Need vericifacation that this will work

    It would be quite a job to look at your very complex design and determine whether it will work or not. Why don't you describe in words what you are trying to do, then maybe someone can help. Bob
  12. BobK

    Capacitor values for opamp circuit and adjustable gain

    Navy Seals Team 6! Bob
  13. BobK

    Drawing 10V from 2 USB ports

    What is it your are trying to do? Bob
  14. BobK

    Capacitor values for opamp circuit and adjustable gain

    No, these are not critical. Increasing the input and output capacitors would increase the low frequency response. The one on the + input is to stabilize the voltage divider and a higher value would not change anything. Bob
  15. BobK

    Follow ME

    Here is my idea. Don't know how practical it is but... If you were wearing a devide that could put out ultrasonic pulse, and was synchornized by an infrared pulse, you could measure the distance to two receivers in corners of the room and this could be used to triangulate your position...
  16. BobK

    Drawing 10V from 2 USB ports

    Do not try to put two USB ports in series. They are likely both connected to the same power supply and when you connect the + of one to the - of the other you will be shorting it. You cannot get 10V this way. Bob
  17. BobK

    150 vdc regulated power supply 1-2 amps

    If you have a resistive load of 120MOhms, it will take a lot more than150V to put 2A through it! Bob Edited to add: Oh, and resistive loads do not have a resonance.
  18. BobK

    Schematic to reality conversion

    The page with the circuit on it suggested 8 AA cells. Bob
  19. BobK

    Transistor Base Resistor, how to calculate

    As knowledgable as you are, I am graitified each time I come up with the same comment as you do, no matter which of us gets it first. Bob
  20. BobK

    Need vericifacation that this will work

    Cost. Complexity. Flexibility. Time. Power. Size. A microcontroller, in the hands of someone who knows what he is doing, would win on all of the above. Bob
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