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  1. hevans1944

    How is this Possible

    That is a serious limitation. Is it because you don't have a cell phone with a digital camera? Or a digital camera of any kind? Or is there a bandwidth limitation that would require an inordinately long period of time to upload an image of any kind? Perhaps you are blind? Will you attempt to...
  2. hevans1944

    Using 2 Sevent Segment to display only 0-15 decimal

    The input to the decoder is binary NOT BCD. That is why the decoder truth table must implement a binary-to-BCD function. Since @mod already has the 7447 BCD-to-7-segment decoder/drivers, all that is needed is the look-up table logic to convert from 4-bit binary to two binary-coded-decimal (BCD)...
  3. hevans1944

    Detecting A Knock Pattern

    The pattern is old and not unique to American English. This Wikipedia article has more information.
  4. hevans1944

    The HANTEK 5102P oscilloscope

    There is plenty of stuff online for you to look at and maybe download and actually read. The 5102P is part of the 5000 series of Hantek Digital Storage Oscilloscopes. The Hantek website has all the information you need. You connect the 'scope to a USB port on your computer using the connector...
  5. hevans1944

    Detecting A Knock Pattern

    The notes at the end of this short YouTube video (located at 0:25) are "shave and hair-cut <short pause> two bits".
  6. hevans1944

    Call Progress tone

    So, the two Arduino Pro Minis will generate the "dial tone" and count the impulses from the dialing mechanism and compare that to the dip-switch binary representation of the pulse count, closing the relay contacts on the RJ11 connector if the "correct" number of pulses are detected. How and...
  7. hevans1944

    Using 2 Sevent Segment to display only 0-15 decimal

    It appears he already knows how to decode 0000 0001 0010 0011 0100 0101 0110 0111 1000 and 1001 as 0 1 2 3 4 5 6 7 8 9 for one 7-segment display. The new task is to decode 1010 1011 1100 1101 1110 1111 and display as 10 11 12 13 14 15, perhaps with leading zero suppression for 0 through 9, for...
  8. hevans1944

    Call Progress tone

    Okay, I suppose the circuit isn't ancient... timeless might be a better description. Op-amps are continuously improved, even in this digital age. The quad op-amp specified (LMC6484IN) has a TI datasheet with a 2000 date and a 2015 update, so it doesn't qualify as ancient. And Arthur Harrison...
  9. hevans1944

    Detecting A Knock Pattern

    So, your spiffy program can detect a "shave and a hair-cut... two bits" knock pattern? I'm impressed. Next will be whistle codes I suppose, maybe followed by voice recognition... hmmm. How about recognizing tunes, like the theme from the movie Close Encounters of the Third Kind?
  10. hevans1944

    AC 117 Volt is it possible to put a DC socket??

    Either way you go, you will be powering your guitar amp with a battery which you will have to re-charge from a wall outlet somewhere. The 12 VDC-to-117 VAC inverter will not be as efficient as hacking your guitar amplifier to provide it with whatever DC it requires from an external battery, but...
  11. hevans1944

    Call Progress tone

    Not sure if "better" is the way to describe an ancient circuit from the previous century, I hadn't realized a Pro Mini was available for two bux (including shipping) on Ebay! So of course that is the way to go. In the end. only you can decided if square waves instead of sine waves produce an...
  12. hevans1944

    help repair router adapter

    Have you discovered a chemical (acetone, perhaps) that will dissolve the foam material? There are probably zillions of wall-wart power supplies out there in need of repair.
  13. hevans1944

    Call Progress tone

    Or you could do it the "old school" way with analog circuitry and save your Arduino(s) for control functions...
  14. hevans1944

    AC 117 Volt is it possible to put a DC socket??

    The inverter is powered with whatever battery you desire. The inverter acts like a portable wall outlet: you plug your guitar amp into the inverter just like you would plug it into a wall socket. No modification of guitar amp is required.
  15. hevans1944

    Explain this circuit: Digital linear PSU

    You should go to the original web site and read all three sections (I, II, and III) to gain a better understanding of this well-engineered dual-tracking ±30 V DC power supply. The op-amps are part of a negative feedback loop comprising transistors T1, T2, T3, T4, T5, and T6. Op-amp IC1A, driven...
  16. hevans1944

    Photoflash capacitors and Charging

    What is "a coil gun of sorts"? What will you use your "coil gun" for? What type of projectile will your "coil gun" launch? How fast will the projectile be when launched from your "coil gun of sorts"? What is the mass of the projectile? What is its size and shape? Will it be dangerous, perhaps...
  17. hevans1944

    Using 2 Sevent Segment to display only 0-15 decimal

    We need to know a lot more about where you are getting the number(s) that will be displayed. Really simple would a sixteen-position rotary switch. Provide some diodes to select segments at each switch position if you use the rotary switch. Please tell us what you are trying to DO.
  18. hevans1944

    NTD4963N

    I think you nailed it. Problem is, DigiKey has zero stock, although the package version with "1" for minimum quantity could be special ordered and someone will cut the ordered quantity from a reel of parts. It does appear to made by ON Semiconductor, so I would check other distributors for stock...
  19. hevans1944

    help repair router adapter

    That's a great way to learn. And since it's a hobby. it's also a labor of love... no monetary reward expected or desired other than saving the cost of a replacement power supply if you can obtain the capacitors inexpensively. Best wishes for your success!
  20. hevans1944

    NTD4963N

    Wow! You really let the smoke out of that one! Please post links to where you found these online.
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