Why is there almost no information on how to connect a schematic ?

Discussion in 'General Electronics Chat' started by Barrythecableguy, Jul 3, 2016.

  1. Barrythecableguy

    Thread Starter Member

    Jun 14, 2016
    31
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    Thank you all again for your help with my previous 555 issues, as stated I am still learning how to read and interpret schematics, I have done a simple Photoshop interpretation of a paper schematic and its completed real world counterpart. There is plenty of info out there on how to read schematics as in symbols and so on but very little on how they are actually connected in the real world and the order in which components go, it seems you just have to work that out for yourself but if anyone has any useful advice, or valuable links, on this matter I would love to hear it.

    If I have made any mistakes in my interpretation then someone please point them out also I welcome additional comments.

    I have uploaded the schematics in both U.S and European formats.

    Thanks

    Barry
     
  2. Lestraveled

    Well-Known Member

    May 19, 2014
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    @Barrythecableguy
    It is not that hard. You will learn very quickly by doing. It is simple; place the parts around the IC that makes the most sense. If a resistor connects between pin 1 and pin 2, then put it there. Try to keep your leads short, but, you don't have to.

    Relax, go forth and bread board and don't forget to have fun.
     
  3. panic mode

    Senior Member

    Oct 10, 2011
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    you are supposed to use your multimeter and probe breadboard to see how are internal connections arranged. i tried marking them some of them up (see attached). your attempt is wrong, it will short 555 output, C1 etc. LEDs must use series resistor too.

    breadboard.png
     
  4. Lestraveled

    Well-Known Member

    May 19, 2014
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    Here is a proto-type I threw together 2 weeks ago. How would you explain this.:D

    DSCF1923.JPG

    It worked fine.
     
  5. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
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    you might wt to look at Fritzing; http://fritzing.org/fritzing-creatorkit/

    The reason you might be having all sorts of trouble is because it's Electrical Engineering.
    You spend lot of time learning the fundamentals.
     
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  6. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    There are guidelines for more advanced circuits, for example high-speed, digital, and RF circuits. Here is a link to just one example for reducing electromagnetic interference (EMI):http://www.ti.com/lit/an/szza009/szza009.pdf

    However, in your example and for many hobbyist examples, the placement of components is based on what looks "right" or is easy to assemble (most construction builds in the sequence of low parts first to tall/big parts), connect wires, and/or route.

    When considering construction on a "breadboard" like you have, Fritzing can be helpful in deciding how to lay out the components and to connect them. There are a few other applications that do a similar thing. I have tried Fritzing, but didn't particularly like it, as it lacked "schematic capture." (At least the version I tried didn't have capture.) What that means is that a program with schematic capture compares how you wired the board with what the schematic says it should be. As a work around to Fritzing or pencil and paper, I just use Eagle and set the grid for the PCB grid to 0.1". Eagle provides schematic capture.

    It is easy to remember how the connections on the breadboard are arranged. So, I use color to differentiate between a potentially existing breadboard connection and a connecting wire that I must add. Arbitrarily, I assign red to existing, and blue to added "wires." I do not show all of the holes to avoid clutter. When I think I am done, I can change the display to show only unconnected pins ("airwires").

    Here's an example from a recent project:
    upload_2016-7-4_6-11-54.png

    An "X" denotes a hole on the board that is not connected.

    There is an adage that placement is at least 80 to 90% of the work of properly routing a board. The Eagle workaround allows one to move parts around and rip-up routed connections freely to get something that satisfies you.

    John
     
  7. Barrythecableguy

    Thread Starter Member

    Jun 14, 2016
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    "Eagle", what is this ?

    Barry
     
  8. Barrythecableguy

    Thread Starter Member

    Jun 14, 2016
    31
    1
    I though I was using a series resistor ? the original circuit also suggested that a cap should be fitted to pin 5 but I really didn't see the need as it contributed nothing to the circuit

    Barry
     
  9. hp1729

    Well-Known Member

    Nov 23, 2015
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    Like most things it builds with experience. Reading seems complicated until you get more experience with letters and how they go together. Components are to schematics as letters are to sentences.
    The more time you spend with it the easier it gets. No secrets.
     
  10. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
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  11. Sensacell

    Well-Known Member

    Jun 19, 2012
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    I see many beginners try to build a complex circuit and get freaked out when it doesn't 'just work' the first time.
    The best advice I can give is to focus on building and testing things in stages, it's less intimidating and leads to higher success rate and better understanding.

    Learn to solder, build things on perf board, solderless breadboards are very flaky and frustrating, they also cause problems for higher frequency work, which is most digital stuff nowadays.
     
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  12. Barrythecableguy

    Thread Starter Member

    Jun 14, 2016
    31
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    Thank You all for your continued assistance, Maplin certainty can't provide any useful advice!

    Barry
     
  13. Papabravo

    Expert

    Feb 24, 2006
    10,137
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    Why would you expect them to provide any at all? They are not in the advice business. It is known, that "free advice is worth what you pay for it".
     
  14. WBahn

    Moderator

    Mar 31, 2012
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    You should put the recommended cap on pin 5. You should also bypass the power supply near the chip (a capacitor between power and common). You can probably get by without doing either of these for many of the circuits you are working with right now, but they really are there for a reason. These capacitors help stabilize the respective voltages which leads to more reliable and consistent operation. As you move to more complex circuits, you will discover that these practices can and will make the difference between a circuit that works and one that doesn't, or is erratic at best. Start learning and adhering to good practices now and you will be a lot less unhappy down the road.
     
  15. WBahn

    Moderator

    Mar 31, 2012
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    He's referring to the LED. You go straight from the 555 output to the LED to common. You need to put a current limiting resistor in series with the LED, so either between the output pin and the LED or between the LED and common.
     
  16. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Keep in mind that the *main* job of a schematic is to show the electrical relationships among the components, not the physical relationships. Often the two go together, but not always. That is why you often see a schematic with a quad opamp or quad NAND gate shown as four separate symbols rather than one 14-pin symbol with all 4 sections inside. Spreading out the functions so they show the signal flow is more important than showing that they are all in one package and surrounded by so much stuff that it's difficult to see what the circuit does. Thanks to online drawing packages there is a new type of internet schematic that is based on the physical device packages and pin connections. Experienced (like, old) designers hate these drawings because they put the cart before the horse. Start with a clear image of what you want to do. Once you have that, how is easier.

    There are books on how to draw a schematic, and large companies and organizations (like the US military) have defined rule sets. But an excellent way for a beginner to learn the rules of the road for drawing schematic is to look at a few thousand. Fortunately, the internet makes this very simple. For example. if you search for 'one watt audio amplifier' or '555 timer schematic', you will get hundreds of images. Even if they don't all make sense, you will see that there are common ways of showing things, like positive voltage symbols point up, ground symbols point down, overall circuit inputs tend to be on the left, outputs on the right, etc. On any forum there will be people with thousands of posts, or people who have been members for many years, or both. These are indicators of experienced designers. Look at their posted schematics and ask questions. I guarantee you will get good advice.

    ak
     
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  17. OBW0549

    Well-Known Member

    Mar 2, 2015
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    If it "contributed nothing to the circuit," neither we nor the manufacturer would be recommending it be included, would we? Just because you don't understand what a component does, DOES NOT mean that it has no purpose!
     
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  18. WBahn

    Moderator

    Mar 31, 2012
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    Though that doesn't mean that anyone (including OBW0549) is saying that you shouldn't ask about what such components do, just that you should have more of an attitude that says, "It must be there for a reason, I just need to learn what it is," as opposed to, "I don't see a reason for it to be there, so I should be able to discard it."
     
    Last edited: Jul 5, 2016
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  19. Dino Cindrić

    New Member

    Oct 3, 2015
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    Hello,
    my advice is that when you start placing components on breadboard, start with more complex components,for example IC's, and then connect other components like resistors,capacitors,diodes etc. It is easier to follow schematic (at least for me,but I think that's the common practice) and maybe you'll figure it out why is that component even there and what's her purpose, and you slowly,but surely (after analyzing "the sea of schematics" ) get some good knowledge of electronics.
     
  20. tredwell

    New Member

    Jun 20, 2016
    5
    0
    sound advice freind, a beginner will learn if the mind is open and accept all known and unkowns. our toes ment nothing but looking and feeling neat as an infant.
     
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