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Posts posted by HarryA

  1. It is difficult to help you with no circuit diagram or photographys. Such problems are often thermal in nature. Something supplying current to the relay over heats and shut down perhaps. 

    "Sometimes when turning on USB memory, or as the selected player plays. " Does that block it or unblock it?

  2. 3 hours ago, reeldeal67 said:

     turntable and it has a grounding issue, a deep hum.

    Does the turntable have electronics in it; preamplifier and power supply perhaps?  The capacitors in older electronics often go bad with age.

    see: https://en.wikipedia.org/wiki/Ground_loop_(electricity)

    note the section: "In low frequency audio and instrumentation systems" and the note near the bottom of the article.

  3.  I would work on the voltage first. Although the specs, say 3.0V 5.0V for the RTS0072 ,there must be problem somewhere.

    The condenser mic. should not be drawing any current, try disconnecting it then recheck the voltage. Pop out the RTS0072 also.

    Specs. for the chip are here (see the second circuit which is like the one you are using):


  4. I looked at your photo in  photoshop where I could enlarge it, looks okay from what I can see of it.

    Check the voltage at the speaker and pin 6 of the LM386 for the 6 volts. Also check the voltages at the mic. and pins 11 & 12 at the RTS0072 for the 4.7 volts off the Zener diode. It is best to check voltages at the IC pins if you can. Also you could in similar manner check the ground connections with the meter. Could be a bad RS0072 ?

  5. There are two types of USB power suppliers; the USB power supply and the USB power supply charger. It appears  you are  using the charger. Consider using a USB hub connected  to the charger then connect your led/motion detector plus a simple LED device.

    The LED device would have a constant drain to keep the charger active?

    see for example(18ma).



  6. Is the action  like this?  I got to many cd's

    Are you comfortable using a micro-controller like an Arduino UNO?

    time:   action                      switch 1    switch 2     
    0:     hv pulses charge C1    at ca        at cd S2's
    1:     C1 is charged to 24v   at cd         at cc
    2:    hv pulses applied to V  at cb         at cc
    3:    C1 drops to 17v            at cd         at cd S2's
    4:    hv pulses charge C1     at ca        at cd  S2's

      cycle repeats


  7. What types of short period are you interested in?  What divert times are you interested in?

    An inductor  in series with the source and load would retard the current going out and when the magnetic field collapses there would be a back emf towards the source.

    A length of coaxial cable would form a delay line. If not terminated to match the cable at the load a pulse would be returned towards the  source. see: analog delay line


  8. Multi-turn pots makes it slow to make adjustments. As Vellerman did not use them perhaps you could replace the pots with good ones like Allen-Bradley pots. Beware  of the various tapers that pots have.  Check Ebay for good prices on Allen-Bradley pots from US suppliers.

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