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  1. John Canon

    The emitter has a higher potential than base ! How?

    When VidGuy says "emitter has a higher potential than base" he is demonstrating a theoretical cutoff mode at the junction level. He is not applying the transistor to a wired circuit. So he is correct at the junction level of discussion, but you cannot put that transisor into a conventional...
  2. John Canon

    Switching multiple lines at once?

    You are on the right track with your diagram, just maintain proper spacing, shielding, and strain relief. That is a lot of wires ... do you plan to use multi-point connectors or just wire the bundles directly?
  3. John Canon

    Switching multiple lines at once?

    You could use four 4PDT relays. Wire the relay coils in parallel. Wire the 16 common terminals to the output. Then the 16 normally open terminals are wired to one set of signals, and the 16 normally closed terminals wired to the other set. The spare set of terminals could drive an indicator...
  4. John Canon

    Ip Camera Question

    You need to convert the 4-pair into a patch cable. In other words take a 3 foot ethernet patch cable, cut it in half, and wire your travelling cable into the middle. Keep the same colors matching at both ends, and keep each pair continuous. If the cable has twisted pairs it helps, but I have...
  5. John Canon

    Remove a component with multiple solders

    If you worry about too much heat, try this: unsolder a few pins or one side then walk away. After 10-15 minutes things will cool down and you can continue.
  6. John Canon

    Help needed

    Simple ... just put a 4.6 volt to 11.6 volt battery in series with your input voltage. Bingo ... 5 volts to 12 volts DC!
  7. John Canon

    Araldite Rapid, Cyanoacrylate & PCB material.. does it stick?

    Don't use fine sandpaper ... you are not looking for a satin surface, you are looking for a rough surface.
  8. John Canon

    Araldite Rapid, Cyanoacrylate & PCB material.. does it stick?

    ... It left the epoxy surfaces beautifully smooth level and flat ... You forgot to roughen the surfaces with sandpaper. So just roughen the "beautifully smooth" epoxy and also the patch material. Then try again with more epoxy.
  9. John Canon

    Generating two complementary signals on 12 V supply on/off

    It doesn't get much easier than this: use a relay with a 12 volt dc coil and with DPDT contacts, or even with SPDT contacts. The relay activates with the 12 volt signal, and the contacts send the 5 volts to one output or the other.
  10. John Canon

    Electronic flourescent tube starter

    Every good Engineer (and Technician!) comes from Humble Beginnings. The Humble part must come immediately from within, not emerge after being hit by the stick. “Do. Or do not. There is no try.”
  11. John Canon

    Electronic flourescent tube starter

  12. John Canon

    Multimeter Blues...?

    To add to your search for meter accuracy, check out Kelvin clips. Link: https://www.allaboutcircuits.com/textbook/direct-current/chpt-8/kelvin-resistance-measurement/
  13. John Canon

    IR Beam Break sensor

    What are your initial ideas?
  14. John Canon

    Electronic flourescent tube starter

    These are all good precautions. Back in high school Electronics class our instructor recommended the "one hand in pocket" routine. So that became the running joke for a while: quick! put your hand in your pocket! your circuit has 2 dry cells!
  15. John Canon

    Multimeter Blues...?

    Good job! Much of electronics troubleshooting is probing and good equipment gets you there. After many years and many multimeters I finally bought a Fluke digital multimeter DMM. The Fluke 110 series has several options. Also you can choose the range for each switch position. My 117 model...
  16. John Canon

    Servo Stop and Reverse

    Mind? Oh, now I get it ... mind ! That's a good one !
  17. John Canon

    momentary pcb switch question

    I got the Dopeler Effect while reading this ...the faster it approaches, the smarter it seems.
  18. John Canon

    Servo Stop and Reverse

    Good old analog! We went to the moon on analog, and the humans did the digital "turn it on.....now" "roger"
  19. John Canon

    capacitor replacement help

    You have some good ideas. The Internet might react better if you actually tried out some of the first steps to see what you get. Nobody wants to spoon feed you through your ideas step by step ... that's your job. Talk about those steps you took and what you found out. Your questions should be...
  20. John Canon

    Change timing period to gadget ?

    The beeper sounds so happy. Why do you want to make it sound sad ?
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