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  1. CDRIVE

    Mic detection circuit

    Yes, many unanswered info requests or at the very least confusing replies. If his mic switch is SP type then he's committed to passing sensing current through the mic coil. This DC current would have to be in the uA region. A comparator circuit would have to be capable of differentiating the...
  2. CDRIVE

    Akai MPK49 repair

    It would appear that the components in question are R1 & C4. R2 (0Ω) looks like it was injured too but it's probably OK. Unfortunately, unless one of our member's is familiar with this board it's unlikely that anyone here will know the values of them. Have you Googled for a schematic? Chris
  3. CDRIVE

    Mic detection circuit

    Thanks for describing those scenarios. I was imagining two singers facing each other and bellowing into the same mic only inches from their mouths. :eek: Chris
  4. CDRIVE

    Mic detection circuit

    WTF! Ya didn't believe me? :eek: Grape growers... Maybe later today. This is Coffee time for me. Lots of it! :D Chris
  5. CDRIVE

    Mic detection circuit

    AK, I guess I'm a Dinosaur that's too behind the times. I honestly didn't think stereo mics existed. Thanks for the enlightenment. Still doesn't seem geographically practical though. :) Chris
  6. CDRIVE

    Change LM2575 minimum input voltage to 8 volt

    I just happened to notice that there's Another Topic that intersects this one. Your LM2575 also has an ON/OFF pin discussed in that topic. ;) Chris
  7. CDRIVE

    Which biopolar transistor to use for switching higher currents using microcontroller

    Dave, you must be feeling better. Glad to see that! Chris
  8. CDRIVE

    Mic detection circuit

    Good info but that's a SPDT switch, not a DPDT. The other tabs you see are the same physical nodes. Slide switches like that are made very inexpensively. What you see there are the same terminals looped into and back out of the switch. If the crimp tabs that you confused with terminals were...
  9. CDRIVE

    Mic detection circuit

    Is that really a stereo mic or is the other element used for noise cancelling? Chris
  10. CDRIVE

    Modernise old rotary telephone

    Ha, the other day I was digging through my junk boxes and found a old Radio Shack Auto-Dialer given to me by a friend many years ago. Like your watch it's placed next to the phone's mic. I think this thing stored multiple contact numbers. Pics & Arduinos probably do have the issues stated but...
  11. CDRIVE

    Problem with picaxe 14m2

    Dev, I posted this CommPort Wizard query on the PICAXE FORUM. The reply that I received was not what I expected but it does explain your confusion with the wizard's "Voltage Test" screen. Chris
  12. CDRIVE

    Which biopolar transistor to use for switching higher currents using microcontroller

    Why can't you use the ON/OFF pin? Chris
  13. CDRIVE

    Modernise old rotary telephone

    I don't know anything about Arduinos other than they're a family of uCs. I would think that they can generate DTMF or Pulse Dial. That being the case I don't see much point in automating the mechanical end of the rotary phone. Why not just use it to just talk and listen? Let the Arduino do the...
  14. CDRIVE

    Modernise old rotary telephone

    I hate to be a killjoy but I don't think this is a practical project. Chris
  15. CDRIVE

    Design help to control 2 relays

    I would think that "In sequence" means one after the other. Like 1, 2, 3, 4 & back to 1, 2, 3, 4 etc. In his case OFF, 1, 2, OFF, 1, 2. As stated the 4017 is applicable. On the other hand, if one relay is always on while the other is off this can be done with a 555, which has enough juice to...
  16. CDRIVE

    Modernise old rotary telephone

    Uh yeah, the rotary phone could be considered a primitive form of digital dialing. I haven't tested my line in over a year but when I did it still accepted it! Chris
  17. CDRIVE

    NPN and relay cct

    To expand on what Steve said... With low side switching you'll eliminate Q2, R2 & R3.;) Chris
  18. CDRIVE

    Mic detection circuit

    Want to get more confused? I have no idea what a stereo microphone would be. After all when you consider the definition of "Stereophonic" I don't see how a "single" microphone can fit the definition. :confused: Chris
  19. CDRIVE

    Change LM2575 minimum input voltage to 8 volt

    Here's one.. http://www.linear.com/product/LTC2960 Chris
  20. CDRIVE

    Change LM2575 minimum input voltage to 8 volt

    I have a folder that has quite a few Voltage Monitor chips but they're designed for use with uCs. These chips draw only a few uA. I would think that there must be Voltage Monitor chips available for voltages >5V. Did you Google it? Chris
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