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  1. K

    Pulse Generating Circuit

    Again, "Would the the 3V input be a pulse or continuous? If continuous, would the switch stop the oscillator even with the 3V present on the input?" ??? Ken
  2. K

    Need help reverse engineering a PCB

    Because of the coil, below the 6-pin IC in the first photo, I think it's some sort of switch mode? buck? boost? converter? power supply. I hope the cable wire...and what's on the other end...is worth the $3.50 to you Daniel. ;) Ken
  3. K

    Pulse Generating Circuit

    Would the the 3V input be a pulse or continuous? If continuous, would the switch stop the oscillator even with the 3V present on the input? I'm thinking a CD4093 configured as a bistable and a gated astable, plus a drive transistor. (never worked with a 4047) Ken
  4. K

    Need some help with building an E.M.P. generator!

    :eek: This has Darwin Award written all over it. Ken
  5. K

    student help

    To add to the reading materials available in books and on-line, hands-on learning is a must. I would recommend looking into the 200-in-1 or 300-in-1 electronics training kits. Google: 200-in-1 or 300-in-1 electronics training kits And do ask questions...the only dumb question is one that is...
  6. K

    Miniture power supplies ?

    Can you post a photo of that charger. I've gutted lots of wall warts for small power suppl PCBs...and have even been able to change the output sensing resistive divider to change the output voltage. This is with power supplies that use standard ICs. Ken
  7. K

    simple circuit drawing software

    I've used ExpressPCB for years. If I just want to do a perf-board version I still use their PCB program to do the layout, but make sure all of the components are fit to a 0.1" grid. Then do point to point with stripped Kynar (wire wrap) wire. I some cases I have to make my own components (piece...
  8. K

    Simple Water Sensor - Alarm when removed from water

    Crab pot floats=Salt water exposure. :( This brings up a "boat load" issues. First the value of R1 will need to be changed...and even then may need to be replaced with a resistor and potentiometer. The issue is that salt water is very conductive, so when the electrodes are lifted above the...
  9. K

    Simple Water Sensor - Alarm when removed from water

    Out of curiosity...what is the purpose of your intended device? Ken
  10. K

    Simple Water Sensor - Alarm when removed from water

    Another simple circuit. Draws less than 0.5uA in the water. Manual switch to turn off when not in use. Use stainless steel electrodes. May have to play with R1 depending on the conductivity of the water. Ken
  11. K

    How do I increase energy flowing into a Capacitor?

    poor mystic, Can you provide a link to support this?: Wiki side note: "Killed by 9V Batteries is an Austrian[1] indie rock rock band." ;) Ken
  12. K

    Turntable strobe

    Glad to hear it works. As Gryd3 said, for more LEDs you can just add more of the Resistor/LED/LED/LED strings in parallel with the existing strings. You will need to use a 12V supply with a higher current rating. Bump the power supply rating by 100mA for each Resistor/LED/LED/LED string you add...
  13. K

    Soft latching power switch

    That type of circuit is what I designed, built, and linked to (push-on/push-off and push-on/program-off) in post #5...along with other peoples' approaches. Ken
  14. K

    Soft latching power switch

    I never wired my circuit with Q2's base current coming directly from Q1's drain, so I can't say. Ken
  15. K

    Soft latching power switch

    Are you sure you have R2 is connected between the MOSFET's source and gate? That should prevent the MOSFET from reacting to the static charge on you hand. With that, you are also leaving the the base of Q2 floating as R1 is connected Q1's open drain that in not conducting except for what ever...
  16. K

    Ideas

    I would guess that your voltage might too high for it. The spec on the web page you linked to said 3-5V. It also may not have been designed to be continuously powered. If I were designing for eventual manufacture (your first post) I would look for motors that you can buy new in quantity, rather...
  17. K

    Ideas

    If your wiring is as shown in the graphic it should work. Ken
  18. K

    Ideas

    On simulating your program, I get errors on both "Run" and the second Pause. I think "Run" is a reserved word, so just change them to "Go". Add "500" after the second "Pause". Ken
  19. K

    Ideas

    It all seem correct. I would try it with the motor. Ken
  20. K

    Ideas

    Please post a schematic of what you have with all connections and non-connections. Ken
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