1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Discrete 555 timer kit

Discussion in 'Electronics Videos' started by misterT, Dec 10, 2013.

  1. misterT

    misterT Well-Known Member Most Helpful Member

    Joined:
    Apr 19, 2010
    Messages:
    2,697
    Likes:
    368
    Location:
    Finland
    Not sure if this fits any other sub-forum so I post it here. Long video, but good waste of time.
     
    • Like Like x 2
  2. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    5,985
    Likes:
    511
    Location:
    Cleveland, OH, USA
    ONLINE
    • Like Like x 2
  3. misterT

    misterT Well-Known Member Most Helpful Member

    Joined:
    Apr 19, 2010
    Messages:
    2,697
    Likes:
    368
    Location:
    Finland
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    5,985
    Likes:
    511
    Location:
    Cleveland, OH, USA
    ONLINE

    The question had to do with the flip-flop and what happens to the inverted output. That drives the discharge transistor, which has been the subject of some discussion in the past on ETO. Anyway, I found this diagram on an educational site (but lost the actual URL), which I think is a pretty good drawing:
    upload_2013-12-10_18-3-43.png


    John
     
    • Like Like x 2
    • Informative Informative x 1
  6. Little Ghostman

    Little Ghostman Well-Known Member Most Helpful Member

    Joined:
    Jan 7, 2011
    Messages:
    3,737
    Likes:
    433
    Location:
    SCOTLAND
    I like the video. How about putting it in the video section? Then it wont get lost in here in a few weeks :( It never occurred to me that you could make a 555 from transistors, i might have a go at doing this over xmas.
     
  7. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    5,985
    Likes:
    511
    Location:
    Cleveland, OH, USA
    ONLINE
    Oh, how far we have come. There are a lot of us here who remember early IC's being advertised with the equivalent number of transistors. Moore's law added some formality to that (http://en.wikipedia.org/wiki/Transistor_count ).

    John
     
  8. Little Ghostman

    Little Ghostman Well-Known Member Most Helpful Member

    Joined:
    Jan 7, 2011
    Messages:
    3,737
    Likes:
    433
    Location:
    SCOTLAND
    Now i think about it is pretty obvious :oops:. I must start to switch on my brain, before touching the keyboard!:rolleyes:
     
  9. cowboybob

    cowboybob Well-Known Member Most Helpful Member

    Joined:
    Oct 22, 2011
    Messages:
    3,037
    Likes:
    478
    Location:
    James Island, SC
    It is fairly remarkable (from an analog-phile's point of view :smug:) what functions a 555 can be configured to perform. From my experience:

    1. Self triggered One shot mono-stable (ms)
    2. Triggered ms
    3. Self triggered a-stable (as)
    4. Triggered as
    5. Self triggered flip-flop (ff) (selectable On or Off initial state of output depending on use of the Reset and Trigger pins)
    6. Triggered ff (as above)
    7. Single or dual triggered ff (in SIM single trigger worked, but in real life never could get it to work :banghead:)
    8. Cascade two of them for dalayed timer (also self or ext. trigger) Cannot cascade three or more.
    9. When used in conjunction with a CV pin bias: Comparator, e.g., level sensor, hysterisis control, etc..

    5. & 6. make a very handy Solid State latch, e.g., as a bounceless, low power Vcc supply (for small mechanical relays, other 555 circuits, etc.).

    3. & 4. are configurable for both frequency and pulse width.

    Did discover that in SIM for an ff circuit, the use of the Reset pin (as a trigger) was simply a bias issue, but in real life I needed to add a cap to ground (from the Reset pin) for output state stability.

    Additional combos of all of the above.

    No doubt more uses that I haven't made use of thus far...
     
  10. ghostman11

    ghostman11 Well-Known Member

    Joined:
    Nov 22, 2009
    Messages:
    1,192
    Likes:
    99
    Location:
    Scotland
    I would love to see one done with VALVES! Now that would be a kit
     
  11. cowboybob

    cowboybob Well-Known Member Most Helpful Member

    Joined:
    Oct 22, 2011
    Messages:
    3,037
    Likes:
    478
    Location:
    James Island, SC
    Bunch of triodes and you're there!

    Oh, how I miss HeathKit :cool:. (Which I could never afford - had to go with Knight Kit...)
     
  12. ghostman11

    ghostman11 Well-Known Member

    Joined:
    Nov 22, 2009
    Messages:
    1,192
    Likes:
    99
    Location:
    Scotland
    I have heard of Heath Kit, Apparently everything in kit form up to a space shuttle :D
     
  13. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    5,985
    Likes:
    511
    Location:
    Cleveland, OH, USA
    ONLINE
    Similar experience here. Everything I built was Knight Kit. The last one I built was the oscilloscope.

    John
     
    • Like Like x 1
  14. cowboybob

    cowboybob Well-Known Member Most Helpful Member

    Joined:
    Oct 22, 2011
    Messages:
    3,037
    Likes:
    478
    Location:
    James Island, SC
    Back in 1958 got the "Span Master' kit for Christmas, then in 59' bought the T-50 xmitter and the R-100 rcvr kits (my first novice Ham set, $$ from a paper route). Got all my parts from Allied Radio in Chicago. Still remember the smell of the components when I opened the box (not really different from today with a box of goodies from Digikey!).
     
  15. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,938
    Likes:
    1,099
  16. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    5,985
    Likes:
    511
    Location:
    Cleveland, OH, USA
    ONLINE
    @KISS
    I cannot get the first link to work. The second is an animation, and they generally turn me off, but it has been swiped by many others including the third. I wish I could find the original source for the animation. It looks like something Tony van Roon would have done, but apparently that is not the case (http://www.sentex.ca/~mec1995/gadgets/555/555.html ).

    The first place I go for 555 information is AN170 from Philips, which for some strange reason is no longer available. I uploaded it to ETO awhile back: http://www.electro-tech-online.com/attachments/555an-pdf.52952/

    John
     
    Last edited: Dec 26, 2013
  17. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,938
    Likes:
    1,099
    I couldn't get it to work either, so I removed it. I should have checked the returned links.
     
  18. glossywhite

    glossywhite Member

    Joined:
    Jan 22, 2014
    Messages:
    77
    Likes:
    4

    I like Dave; he's a lovely guy when you get used to him, and he puts A LOT of hard work and detail into his videos; detail that most people overlook, forget or just cannot be bothered with. I admit, however, watching this kit being built *in realtime* was one of the most tedious things I've ever suffered... but I love 99.999% of his videos; he's a good bloke, a nice one. :)
     
  19. Miervaldis

    Miervaldis New Member

    Joined:
    Sep 3, 2014
    Messages:
    3
    Likes:
    0
    Awesome video! I love it :) And yes, it was interesting even after an hour :D
     
    • Agree Agree x 1
  20. misterT

    misterT Well-Known Member Most Helpful Member

    Joined:
    Apr 19, 2010
    Messages:
    2,697
    Likes:
    368
    Location:
    Finland
  21. Miervaldis

    Miervaldis New Member

    Joined:
    Sep 3, 2014
    Messages:
    3
    Likes:
    0

Share This Page