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  1. hevans1944

    CircuitMaker 2000: Any users here?

    @terrypin I still run XP Pro, but that's because I am lazy, not because I don't have other computers running more modern operating systems. You should upgrade your computer and download the latest version of Circuitmaker 2000. Or do as Martin said and switch to LTSpice which runs okay on my XP...
  2. hevans1944

    What power source and resistors are required for the circuit below?

    I am not sure why you are so adamant about not using appropriate technology. Just because you want to do something does not mean you can do it. It looks like you either do not have enough IR illumination reflected from the table, or the photodiode current does not drive the transistor...
  3. hevans1944

    Starting DC motor by squeezing handle

    Actualy, the counter-rotation from the reaction torque on the propeller is a "feature" of this new toy. It allows a full 360 degree panoramic view. Rotation speed is varied by extending the other arm and legs to change the moment of inertia about the ascension axis. See photo of Peggy Fleming...
  4. hevans1944

    Writing to line 3 and 4 of an LCD

    I LOVE problems the OP solved without our help!
  5. hevans1944

    Starting DC motor by squeezing handle

    @Martaine2005 not turning on in the central points is easy: it's called a window comparator. But it does need an analog signal representing the squeeze pressure. I was thinking of thick-walled large-diameter Tygon flexible tubing when I wrote my first response. If you fill this with water or...
  6. hevans1944

    Starting DC motor by squeezing handle

    A MEMS pressure sensor is quite inexpensive, but they usually do require some signal conditioning. See attached datasheet.
  7. hevans1944

    Starting DC motor by squeezing handle

    @homer2121 hasn't replied to our comments yet, but I can't help but notice this is yet another example of a newbie posting their "solution" to a problem without telling us exactly what the problem really is. For example, stating that the handle must be incompressible, like a broom-stick, without...
  8. hevans1944

    Starting DC motor by squeezing handle

    I didn't know you could buy these off-the-shelf. Could you provide a link? Does it activate a switch in the box or some sort of pressure transducer? Looks like it could do a nice job of measuring squeeze pressure. Pretty blue color too! What are these normally used for? What do they cost? Edit...
  9. hevans1944

    Starting DC motor by squeezing handle

    Lets see if I understand this... someone picks up the handle and the fan motor starts. If they squeeze hard enough the motor stops. If they squeeze a little harder the motor starts again. The fan motor is stopped in between these two levels of squeeze. If they lay the handle down you want a...
  10. hevans1944

    It's in the box

    Wooden boxes with finger-joints for electronics projects! I'll have to dust off my Shopsmith and maybe buy an Incra jig... Good job, Steve!
  11. hevans1944

    Buying soldering iron

    There may be a difference in the temperature sensing element that could make the Weller tips incompatible with the import version. But at that price, you can buy and try without being out too much cash. As for the tips, make sure you keep them well-tinned, wiping on a damp sponge between use...
  12. hevans1944

    Piezoelectricity

    I can hear it now! A subway platform filled with the sound of hundreds of loud crickets! Or, how about an airport concourse resounding to the noise of thousands of crickets! Wonder what the TSA would think of that?
  13. hevans1944

    How do i power this laser

    I should live so long!
  14. hevans1944

    Piezoelectricity

    Yeah, my "gut" feeling is those gas igniters produce several thousand volts judging by the size of the spark and the distance the spark jumps. One millimeter was just a guess based on casual inspection of a few lighters I have seen, it could be greater requiring more voltage to arc reliably. And...
  15. hevans1944

    Piezoelectricity

    The initial pulse is DC. There will be a much smaller voltage generated on the re-bound, and possibly a damped oscillation. I haven't tried experimenting with these things, but basically you can't have charge appearing out of nowhere, so whatever charge separation is created by compressing the...
  16. hevans1944

    How do i power this laser

    That is an excellent example of a non sequitur. Both of them could be broken. Caveat emptor. Welcome to Electronics Point.
  17. hevans1944

    Piezoelectricity

    The voltage is sufficient to create a small spark over a distance of about one millimeter or so. Wikipedia claims this is on the order of 800 V. The current is very small, probably less than one milliampere, and exists for a very short period of time because it is produced by a mechanical...
  18. hevans1944

    Working with high voltage pulses

    Another amazing find from New Zealand! Thank you very much, @GPG. If this is typical of the work of post-graduate students at Massey University we could use some more of it here. Very professional, very complete, very well-researched master's thesis paper. Kudos to Glen McGillan. BTW, this is...
  19. hevans1944

    A hard to resist problem

    The power rating on ANY device depends on how much temperature rise it can withstand before catastrophic failure occurs. As @cjdelphi noted, a block of ice with the resistor embedded in the ice will turn a 1/4 watt resistor into a 10 watt resistor at least until the ice melts. Even so, the heat...
  20. hevans1944

    Luminousity of standard RED LED

    Do you even know what the definition of luminosity is? Or how to measure it? Usually we talk about LED brightness instead of luminosity. There is no such thing as a "standard" LED. What you have could be a considered a "typical" LED though. You can power that puppy up with a five or six or even...
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