Jump to content
Electronics-Lab.com Community


  • Posts

  • Joined

  • Last visited

  • Days Won


Posts posted by HarryA

  1. If it interest you, I could program the micro-controller for you.  That would give you an introduction to micro-controllers. The micro-controller is about 21$, a LCD  about 13$, You would need a 9 volt battery, a battery connector, a battery to micro_controller connector, and a switch also.

    An assortment of colored wire would be helpful. Plus a plastic or metal box to pack it all into.

    If you are checking your cables near a computer you could uses the computer as a simple display device instead of the LCD.

    LCD : https://www.amazon.com/SunFounder-Serial-Module-Arduino-Mega2560/dp/B01GPUMP9C/ref=sr_1_1_sspa?adgrpid=1335907194272933

    Micro-controller: https://www.amazon.com/ELEGOO-ATmega2560-ATMEGA16U2-Arduino-Compliant/dp/B01H4ZDYCE/ref=sr_1_2_sspa?crid=1L06F0IP302BX&keywords=Arduino+R3+Mega2560&qid=1684882151

    wire: https://www.amazon.com/TUOFENG-Hookup-Wires-6-Different-Colored/dp/B07TX6BX47/ref=sr_1_3?keywords=colored+wire+spool&link_code=qs&qid=1684885902&sourceid=Mozilla-search&sr=8-3


  2. No, just simply add a capacitor to the  AOUT  terminal  ahead of the speaker from your board.  Can you trace pin 5 of the LM386 directly to the AOUT terminal ?

    There may or may not be a small capacitor and resistor connected to pin 5 also.

    UPDATE: It look like the board already has an output capacitor. The yellow  227C is a 220 microfarad capacitor. So you do not need to add one. see:  https://www.ebay.com/itm/391354402991?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338766894&toolid=20006&

    Just connect your speaker to the output terminals.


  3. It looks like  the unit you have is designed to work with a high impedance load like the input to the Arduino. Typically for  a LM386  driving a 8 ohm speaker a 220 to 250 microfarad capacitor is used with the negative lead to the speaker.  Try adding one to your unit. see the circuits here:




  4. 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?

  5. 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.

  6.  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):


  7. 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 ?

  8. 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).



  • Create New...