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Posting a two page schematic

Discussion in 'General Electronics Chat' started by MrDEB, Jun 19, 2012.

  1. MrDEB

    MrDEB Active Member

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    Will look into it.
    The program has a glitch in that connecting to a bus it doesn't connect as wanted sometimes. It asks if I want to change related wires only or ??
    Kinda confusing.
    At least I go a decent schematic to post at a good level of detail.
     
  2. MrDEB

    MrDEB Active Member

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    correct schematics

    and large pics.
    I hope I corrected all the BIAS connections. The program kept changing all similar when I just want to change the one bus connection.
     
  3. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Since your two schematics have different part numbers then I will not list all the errors with bias and ground.
     
  4. dave

    Dave New Member

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  5. peterpanpumpkin

    peterpanpumpkin New Member

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    I'm sorry but your schematics are basically incomprehensible.

    Schematics should show connections; buses usually contain the 8 lines of a port or the transmit/receive lines between chips and subsystems. Instead of actually showing connections, you've taken a shortcut of collecting anything that was inconvenient to show and run it into one jumbo line with little labels here and there. Instead of graphically representing the circuit you've actually shown nothing.

    There are some conventions that should be followed to make schematics understandable. Signals start at the upper left and flow to the lower right. Sometimes you can't follow this convention but the diagram is much easier to understand if you do.

    I'd also suggest you keep each iteration and add a revision number so you can keep track of what's what. my-crappy-circuit-1, my-crappy-circuit-2, my-crappy-circuit-3....along with some notes about what's changed each time. Sooner or later AudioGuru is going to tire of correcting the same errors again and again and again and again and again....
     
  6. MrDEB

    MrDEB Active Member

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    I never knew that signals start at upper left and flow to lower right.
    As far as the bus that's what DIPTRACE uses. Perhaps I am doing it wrong?
    You mention 8 lines of a port? Are you referring to Vcc, Grd ??
    Need to figure out what two part numbers Audioguru is referring to?YES on the revision numbers. I get lost as well. Trying to learn something in the process.
    Will look up on search about schematic nomenclature.
    An article suggestion is in order for Electrotech.
     
  7. MrDEB

    MrDEB Active Member

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    Going to redo entire schematic with input at upper left and output at lower right.
    Using port connections for V+, GRD, Bias
    us no bus lines (to confusing )
    any other suggestions or reference material for drawing a PROPER schematic.
    DIPTRACE has a HIERARCHY connector and a HIERARCHY block. Have yet to figure out but ??
    I really want to make good readable schematics. My first schematics were horiable using EXPRESS PCB.
     
  8. MrDEB

    MrDEB Active Member

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    completly redone

    Re organized and using port connections.
    Input at upper left and output bottom right
    Got complete schematic on one page.
    Hopefully this is all correct as far as schematic layout etc.
     
  9. audioguru

    audioguru Well-Known Member Most Helpful Member

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    A schematic looks clearer when parts are all in a line so that there is no wasted space beside them. Then the schematic can be fairly compact then can be enlarged to fill a page.

    I cropped many of your schematics then they were much clearer.

    The fonts used for part numbers on many of your schematics look odd and are difficult to read.
     
  10. audioguru

    audioguru Well-Known Member Most Helpful Member

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    1) Your new schematic still has the wrong values for input coupling capacitors. Yours are huge electrolytic types and their polarity is unknown and might easily be wrong. Much smaller film (nonpolarized) capacitors should be used.
    2) Your volume controls are completely wrong.
     
  11. MrDEB

    MrDEB Active Member

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    migrating from one schematic to another I guess I got lost as you and Pumpkin mentioned.
    will make changes as suggested.
    Will look if I can redo something w/ the fonts
     
  12. MrDEB

    MrDEB Active Member

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    here is revised font

    The program recommends vector but this schematic post is using truetype
    Boy your right with everything in a row it is easier to read.
    I found out how to connect nets with out wires and automatically connect Vcc, Grd etc to components. Helps eliminate a mess of connecting wires etc.
    THANKS again to you and Pumpkin for setting me straight or should I say straighter.
     
  13. MrDEB

    MrDEB Active Member

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    some of the caps may be backwards but there is no polarity. I think pin 1 is always connected as IN and pin 2 as OUT or grd?
    some of the caps I purchased are tant type which have a polarity so when I assemble I need to be sure.
     
  14. chemelec

    chemelec Well-Known Member

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    When drawing schematics, they should always be done as "TRUE" Black & White. NOT Gray Scale
    And I Recommend drawing all lines with "2 bit" width.
    Now these can be Scaled up or down, Without any loss of Quality or resolution, especially good when Printing them.
    However True B/W Can't be saved as JPG, as it will change to a "Gray Scale" and lose quality.

    Always save them as a Tif, Gif or Png file.
    But Tif Produces a VERY LARGE FILE.
    Gif and Png are much smaller files.
     
  15. audioguru

    audioguru Well-Known Member Most Helpful Member

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    I notice a capacitor polarity problem:
     
  16. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Your amplifier is an oscillator:
     
  17. MrDEB

    MrDEB Active Member

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    I made all the suggested corrections.
    Curious if the text is better seeing how its true type instead of vector?
     
  18. MrDEB

    MrDEB Active Member

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    I think I am ready for PCboards

    been fine tuning changing little things like a switch and power terminal. Planning on using a 9V rechargeable battery for compactness.
    The suggestions on drawing a schematic really makes reading schematic better
    THANKS
     
  19. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Coupling capacitors are missing that should feed the volume controls from the opamp tone controls outputs.
    The tone controls outputs have a DC voltage but the volume controls do not want DC, they use only AC from a coupling capacitor. Then the 10k volume controls set the inputs of the TDA2822M audio power amplifiers at 0V DC.
    A film capacitor value of 330nF (0.33uF) will roll off frequencies below 49Hz.

    You have C9, C2 and C18 all in parallel for the bias. Only one capacitor is needed and it should be a 4.7uF electrolytic.
    You have C16 as a 0.1uf supply bypass capacitor. It should be a 10uF to 47uF electrolytic.

    Sorry, I did not look at your pcb layout.
     
  20. MrDEB

    MrDEB Active Member

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    made a few changes

    made suggested changes and found I had V+ connected w/o the switch controlling the power.
    Have V+ as 9V battery input and V_-sw for all connections after the switch
    No power supply circuitry just a 9V battery? Think maybe some sort of regulator?the amp 2.5V-18V and the Op amps 1.5 - 15V
    amazing how many little issues creep up.
     
  21. MrDEB

    MrDEB Active Member

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    Contemplating just a simple 5V lp 2931 LDO regulator should do the deed. This will then produce a stable 5v power supply thus preventing a yo yo supply voltage.
    a ,1uf on IN and 100uf on OUT lines
     

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