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  1. K

    4 players quiz game using relays

    Interesting! I would never eliminate electro-mechanical relays, or switches, or lamps or wires from my "electronics" resources because there are newer alternatives. I occasionally use old technology because that's what I have on hand. And, still call it electronics.. ;) Ken
  2. K

    supply electrode with the humidity of the soil

    Unfortunately that link doesn't show the schematic. Ken
  3. K

    supply electrode with the humidity of the soil

    No. Slowly switching the output high (+5VDC) and low (0VDC) does not produce AC, just "pulsating" DC. You actually have to switch the polarity. You can do that by feeding the output of the 555 (or 4093 in my circuit) oscillator through a capacitor, into a resistive load. And to do that with a...
  4. K

    supply electrode with the humidity of the soil

    I've used several versions of that 4093 circuit successfully in water lever detection. It might require a comparator at the output of the voltage doubler (or better quadrupler) instead of the gate for this application. Ken
  5. K

    difference

    Specs look very similar and pinout is the same. i would try it. Ken
  6. K

    difference

    Have you compared the datasheets? https://www.fairchildsemi.com/datasheets/KA/KA358A.pdf http://www.farnell.com/datasheets/1874566.pdf What are you going to do with it? Ken
  7. K

    Making a beacon

    "...I don't mind contacting a high tech company, ..." ???? Isn't a student science project supposed to be within the capability of the "student"? Seems like she should be the one asking questions here? I can almost always tell when a student project has been overtaken partially or completely...
  8. K

    need help finding ac/dc adapter

    Jameco is a great supplier to hobbiests. I've used them for years with no problems. Ken
  9. K

    Flight Simulator USB controller

    Google: diy flight simulator controls Ken
  10. K

    I want latest electronics seminar Topic

    So you want "us" to search out all of the "latest" seminars on all of the "latest" technologies on all fields involving electronics, so "you" can choose something that might interest you? I think if you want more help, you need to narrow your focus. Ken
  11. K

    Need schematic for a Realistic PA amp Model MPA 20

    A little more info here: http://support.radioshack.com/support_audio/8736.htm Also Google Images: Realistic MPA 20 Schematic I find Google Images a great source for schematics. Ken
  12. K

    I want latest electronics seminar Topic

    I just Googled: free latest electronics technology seminars Maybe something here would interest you: http://www.circuitstoday.com/electronic-seminar-topics or here: http://freevideolectures.com/Subject/Electronics# or you might find a topic here that you can search on...
  13. K

    Obtain the schematic circuit by pcb

    Do you not have the Circad software? If you do does it create an image of the PCB? If so can you just do a screen-print and use their reverse engineering option. Or do you just have the file with no supporting software? If so, maybe you could you could start a thread on this forum (or other...
  14. K

    Turntable strobe

    Chris, There now appear to be other options to get Gerber files from .pcb files. Google: ExpressPCB to Gerber I see one will do it for $5. http://www.stewartinstrumentsinc.com/ I haven't tried any of them, but now will have to look into it in the future. :) Ken
  15. K

    Obtain the schematic circuit by pcb

    Looks like Circad has a way of Reverse Engineering a single sided PCB: http://www.holophase.com/reverse.htm Ken
  16. K

    240v to 5v for wireless charging circuit

    There are a lot of small 5v/2A switch mode power supply modules/PCBs out there off the shelf. Google: 5V/2a SMPS modules You will have to look around a little to find one close to your dimensions and input voltage. I've also gutted (very carefully) wall warts to get small power supplies circuit...
  17. K

    240v to 5v for wireless charging circuit

    How much current do you need for the 5V circuit? How much room do you have in the lamp base? Ken
  18. K

    Turntable strobe

    Or, to add the Gryd3's options, for simple layouts like yours I use 0.1" grid perf-board with individual solder pads. I make sure all of my component leads align with the 0.1"x0.1" grid in my PCB. Then I use #30 Kynar wire and do point-to-point wiring between pads, following the PCB trace...
  19. K

    Turntable strobe

    Chris, When you post the ExpressPCB pcb files, also post the associated .sch files. Since they're linked, it makes error between the schematic and PCB layout much easier. Good work! Ken
  20. K

    Turntable strobe

    Work!? Personal life!? Where are your priorities man? ;) Can your post the .sch and .PCB files http://www.cui.com/product/resource/pj-202a.pdf It depends on the wiring of the wall wart plug. Most are + for the center and - for the barrel. Those are pins 1 and 2 on that jack in the data sheet. 3...
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