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  1. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    I think it's time for some basic troubleshooting. Wire your motor as shown here and tell us if the motor runs when you close the switch. If you don't have a switch then just use a jumper to open and close the base circuit. This way we'll know if your transistor is still with us or gone to...
  2. CDRIVE

    Voltage Follower Doesn't Work

    AK, is that quote plagiarized or yours? In either case I love it! If yours I love it even more. ;) Chris
  3. CDRIVE

    Simple mesh or junction method

    In perfect inductors the current lags the voltage by 90°. In a perfect capacitor the current leads the voltage by 90°. So the formulas for Xc & Xl don't rely on the current and voltage being in phase because that's not going to happen. If it did it wouldn't be a capacitor or inductor. Chris
  4. CDRIVE

    NPN circuit isn't switching after power change

    Dave have you been tipping the glass a bit more today? :D Chris
  5. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    Ah, that too! As usual photos clear up mysteries. ;) Chris
  6. CDRIVE

    Circuit Which Turn On The Light As A Response To A Specific Sound Sequence ?

    Welcome to EP. The most practical approach would be a microcontroller. Chris
  7. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    Looking at your photo I can confirm that you didn't wire the transistor as Bob suggested. From what I can derive from the photo it's still wired as a Emitter Follower, which as Bob pointed out is not the best configuration for saturating a transistor. That said an Emitter Follower should still...
  8. CDRIVE

    NPN circuit isn't switching after power change

    I forgot to mention that since I was unable to read the description of your sensor I'm also unable to determine if your output pin is relay contacts or possibly open collector logic. If either case is true you don't need the 2N2907 as the output pin can be directly connected (no resistor either)...
  9. CDRIVE

    NPN circuit isn't switching after power change

    The 2N2907 is a PNP which leaves me to believe that your sensor output goes low when triggered. If that's the case your circuit should look like this. Chris
  10. CDRIVE

    NPN circuit isn't switching after power change

    When I clicked on your sensor link Norton blocked it reporting it to be a known DANGEROUS website?? Chris
  11. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    When weird results are posted regarding circuits that we're intimately familiar with it's time for some clear photos. Chris
  12. CDRIVE

    Identifying an individual to a system - Ardiuno

    I wonder if having it recognize your keyfob would be doable? It would eliminate a phone altogether. If not ebay has heaps of kefob transmitters and receivers ...cheap! Chris
  13. CDRIVE

    Identifying an individual to a system - Ardiuno

    If your talking about a land line phone connected to your arduino you could send it DTMF codes to recognize you. Chris
  14. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    This makes no sense. If you wired the motor as Bob described you shouldn't read any voltage on the Emitter as it would be connected to GND. If that little 2N2222 passed 4.8Amps for anything other than a short pulse time it should have destroyed itself. Chris
  15. CDRIVE

    NPN circuit isn't switching after power change

    I'm a bit confused here as I see two things that don't make sense. For one thing the battery polarity is opposite of the ± input on your sensor. This is just probably a drawing error. My other issue is your USB keyboard. USB keyboards don't output 5V they input it from the computer's USB port...
  16. CDRIVE

    Modifying AGC circuit

    My statements were specific to a midway biased single supply OpAmp. Nothing more and nothing less. Chris
  17. CDRIVE

    Simple resistor overheat problem

    Font Family can sometimes effect this. Are you sure you're using the number pad and not number/symbol (also called number/operator) keys? In any case as Bob pointed out we have an Ω, μ & ± symbol set in our toolbar. Chris
  18. CDRIVE

    Simple resistor overheat problem

    Keyboard wizardry has become a lost art. Prior to the advent of the mouse stuff like this was common knowledge. It is sadly being lost along with the exceptional power that the Command Line provides for those that know how to use it. http://usefulshortcuts.com/alt-codes/greek-alt-codes.php...
  19. CDRIVE

    Modifying AGC circuit

    OMG! I just discover ceramic caps >0.5µF and within minutes I discover flexibles too!! Chris
  20. CDRIVE

    Simple resistor overheat problem

    This Ω symbol was generated by holding down the ALT key and pressing 234 on the number pad (not the number keys below the function keys) found on most keyboards. Chris
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