Still stuck on schematics

Discussion in 'Homework Help' started by Kid347, Sep 20, 2016.

  1. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    I am still stuck on reading and understanding schematics. Can someone please point me in the direction on where or how I can learn what the connections are doing. I am attaching a schematic of a circuit that I have not been able to complete for months now. my first problem is C4 I know that one end goes to ground but where does the other end go? is it to R3, to 5v/12v, or does it go to pin 4 of the 555 timer. Also C1 I know that one end goes to ground but the other end does it go to VR1 or to pin 6. And C2 again ground on one side but on the other is it R1 or to pin 8. I am very clear on the single connections like pin 1 go ground, and pin 5 go ground through a .1uf capacitor. but lost when they have multiple connections. All I have is this web site, some books and google, but I can't find the answer to this problem of mine. thank you in advance to anyone who can point me in the right direction.
     
  2. SLK001

    Well-Known Member

    Nov 29, 2011
    822
    229
    The black lines are connections, so C4 goes to R3, 5V/12v and to pin 4 and pin 8 of both 555s, plus C6, R1, the speaker, D1 and C2.
     
  3. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    Is it possible to make all those connections on a breadboard?
     
  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Kid347 and atferrari like this.
  5. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
  6. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0

    I looked it over and there is some really good info, but I still can't seem to find the specific explanation of how the multiple connections work.
     
  7. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    It's a 2 dimensional drawing representing a 3D object, so yes you can build it for real in 3 dimensions. The spots where wires cross are pretty much the only spots where you need the 3rd dimension.

    My breadboard allows 6-8 (I forget which) wires at each node. If you need more, you just hop to another node.
     
  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Here is a breadboard setup ... I included the schematic and the breadboard. Can you see how the "multiple" connections are accomplished?
     
    Kid347 likes this.
  9. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    Very helpful, this is exactly what I am looking for. Do you know where I can find more examples like this?
     
  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    No I don't.
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    Try here
     
  12. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    Joe, this is very helpful, do you know where I can get to look at more examples. I don't know why none of the books or web sites explain the connections. Either I over thought, or added 2+2 and came up with 5. But this has been giving me trouble for well over a year now. Thanks to your post I think I am on my way to figuring this out. Thank you again.
     
  13. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    You have showed us your schematic. You have not shown us your attempt to breadboard it. If you don't have anything on your breadboard, insert the chips and connect just the power layout to the chips, every connection directly connected to positive and ground. Then post a picture of your breadboard.

    This way we can see something other than words on this screen.

    Remember, I only want to see the power connections to the chips.

    I don't like troubleshooting a breadboard that looks like this, and there have been worse than this:

    [​IMG]

    So do the job neatly.
     
  14. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    Joe: this is my latest failed attempt, I am attaching the pictures. Let me know if you want any other info.
     
  15. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    What test equipment do you have?

    On edit:

    If you have a DMM, check the voltages to ground on every pin of the chips and the transistor.

    Record and post them.
     
    Last edited: Sep 21, 2016
  16. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    IC 1 farthest from transistor Pin1=0v, Pin2=.160mv, Pin3=5.9v, Pin4=7.0v, Pin5=4.6v, Pin6=.160mv, Pin7=.156mv Pin8=7.03v.

    IC2 closest to transistor Pin1=0, Pin2=.160mv, Pin3=5.7v, Pin4=7.0v, Pin5=5.02v, Pin6=.158mv, Pin7=.157mv, Pin8=7.03v.

    Transistor TIP31 Base jumps from .005 to 000mv, collector .003, Emitter .000
     
  17. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    You need to look how you have that transistor connected or that transistor might be defective.

    Post a clear picture of just the transistor area.
     
    Last edited: Sep 21, 2016
  18. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    Here are the pictures of the Transistor, also I took a picture of the readings from a little tester.
     
  19. Kid347

    Thread Starter Member

    Aug 14, 2015
    68
    0
    I am also not sure what C4 connects to, I know that one end goes to ground, but I am not sure where the other ends go.
     
  20. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    C4 connects between the +V supply and ground. Those lines represent a wire ... and the dots represent a connection.

    If you changed any connections, remeasure the transistor connections to ground.

    I don't like the fact that the Q1 base is too low, it should be closer to 0.5 to 0.7 volts. I don't like the fact that Q1 collector is zero. It should be higher, possible about half the supply voltage or more depending on how your DMM samples the signal.
     
Loading...