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  1. BobK

    Why I prefer electronics to plumbing

    Look at my picture! I am Gomez. We actually won 3rd place in a costume contest last Halloween. Bob
  2. BobK

    Buck-Boost Inverting Power Supply

    What is the input power? Most vehicles already have 12V or 24V power. Bob
  3. BobK

    voltage to frequency

    If the frequencies are really that low, a microcontroller would be the simplest solution. Bob
  4. BobK

    Would a 3V 13100rpm motor be able to pull 3lbs of weight?

    Gryd3's calculations are a theoretical maximum. I would derate by about a factor or 2 to estimate what it might really do. Bob
  5. BobK

    Measuring the speed of a Frisbee & Boomerang

    Have you considered the effect of that mass on the rotation of the Frisbee? I think it will degrade the performance a bit. Bob
  6. BobK

    Basic Physics Question

    This is why I like my voltage as height analog. Think of water falling through a waterwheel. No water is lost, but energy is lost as the height of the water is changed. Mass in a gravitational field is equivalent to charge in an electric field. Potential in the first case replaces height in...
  7. BobK

    Problem: Schmitt Trigger not giving ON/OFF output

    If a Zener diode is too slow, a '741 is certainly also too slow. Perhaps I am dense, I still don't see how a Zener diode can force a voltage to zero. Bob
  8. BobK

    Why I prefer electronics to plumbing

    This morning, I found that the drain for the washing machine had cracked leaving water all over the floor. A typical plumbing emergency. So naturally, I went to my well-stocked hat rack and put on my plumbing hat. The connection into the drain pipe was old iron pipe. The old fitting did not...
  9. BobK

    dc motor questions

    Yep, looking at an Energizer datasheet I get 60Hrs to discharge to 1.2V. http://data.energizer.com/PDFs/E91.pdf Bob
  10. BobK

    Radio Reciever Circuit

    It is an inverter. It is being biased into the linear region by the feedback resistor. Similar to the first stage, which is a transistor with a resistor from the collector to the base. Bob
  11. BobK

    Voltage rating of Capacitors.

    It is not a matter of exploding, it is a matter of degrading. Electrolytic capacitors essentially have material plated on a substrate. A voltage higher than the rating reverses this process and the material is removed, eventually causing failure. Bob
  12. BobK

    HELP! Wireless Keyfinder Project

    Actually I got more than that as an employee, when stock and bonuses are included. But I am retired now. And our engineers in China earned about $15 an hour, which is a lot more than $111 per month. Bob
  13. BobK

    HELP! Wireless Keyfinder Project

    Wow, where do you get brilliant engineers that work for $111 per month? I get more than that for an hour. Bob
  14. BobK

    Help optimizing byte compare algorithm

    Not sure why people are surprised to find a goto instruction. It is the same thing as a jmp or br instruction on other assembly languages. Test and skip instructions are a little more flexible than conditional branch instructions since they can test any bit in any registers instead of just the...
  15. BobK

    Question about a dc motor

    With the transistor or relay being optional if the current the motor draws is <200mA and you use an NE555 chip. Bob
  16. BobK

    What does this symbol mean

    I second your educated guess with my educated guess. I was going to post that, but I was not certain. Bob
  17. BobK

    AC/DC converter - If I cut/ splice the wire can I use it in my car?

    Yes, the outside of the plug is - and the inside is +, as indicated by the diagram right above the red circle in your picture. After you cut the wires, check which one is connected to the outside of the plug, and this one will connect to ground in the car. Bob
  18. BobK

    Help optimizing byte compare algorithm

    read movfw byte ;perform framecheck subwf framing, w btfss STATUS, Z goto read The Z bit of the STATUS register is set when an arithmetic instruction results in a 0. So you test this after subtracting the two. XOR would work as well, but is more obscure, to compare two values...
  19. BobK

    How to design a Flip Flop using 555 Timer ?

    Because I have been familiar with this terminology for at least 40 years. And I checked Wikipedia for the definition of flip flop currently accepted. Bob
  20. BobK

    Multiple Miniature speaker project

    Did you want different sounds coming from each speaker? If so, you can only get 2 from an MP3 player at the same time. If not, why do you need multiple speakers? Bob
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