How a 555 Works as a Timer.

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  • čas přidán 22. 07. 2024
  • In this video I explain the building blocks of a 555 chip and how it interacts with the components you connect around it to become a “Timer”!
    I talk through each stage of the 555 including
    - Voltage Divider (comprising of three 5K resistors)
    - Two Comparators
    - The Flip-Flop
    - NPN and PNP Transistors utilised for Discharge and Reset
    We explore the Charge and Discharge times as the capacitor oscillates between the 1/3rd and 2/3rd voltage levels and verify that with an oscilloscope.
    If you are interested in the handy configurable Resistor boards I utilised you can purchase them from Amazon here:-
    amzn.to/3RYiX75
    For more information about Voltage Dividers, see one of my previous videos here:-
    • What Are Voltage Divid...
    Timeline
    -----------
    00:00:00 - Introduction
    00:00:59 - PKAE Electronics Intro Theme
    00:01:09 - Internal Stages starting with Voltage Divider
    00:02:29 - Two Comparators
    00:04:16 - Control Voltage Pin
    00:04:32 - Flip-Flop & Output Driver Stage
    00:05:40 - SR Flip-Flop Explained
    00:07:27 - NPN Discharge Transistor
    00:07:50 - PNP Transistor for External Reset
    00:08:14 - Summary of Stages
    00:08:39 - Comparator/Flip-Flip Experimenting (Theory)
    00:15:54 - Comparator/Flip-Flip Experimenting (Bench Testing)
    00:17:58 - Astable Circuitry - External Capacitor and Two Resistors
    00:21:20 - Bench Testing Astable Mode
    00:22:48 - Datasheet Astable Circuit Diagram
    00:23:27 - Control Voltage Capacitor (Stability)
    00:23:53 - Timing Calculations (On and Off Times)
    00:25:41 - Bench Testing Timings with Oscilloscope
    00:29:06 - Timing Summing Up
    00:29:17 - Frequency Calculation
    00:30:12 - Wrap Up.
  • Věda a technologie

Komentáře • 421

  • @dougtaylor7724
    @dougtaylor7724 Před 13 dny +161

    Back years ago when I taught myself electronics I bought one of the multi purpose board kits you can use to make 200 or so projects.
    When I played with a 555 that was the most amazing chips ever. Make timers to turn on and off at different times.! Once made a timer that took a month to turn on. After calculating the resistance and caps it was put in the living room and did nothing. Just sat there waiting to trip on. The wife thought I lost my mind. One Saturday about 4pm it came on. The timing was about 6 hours different from what I calculated. But, it was amazing a $1 circuit went off that close after 32 days. And I made it do that! The wife really thought I had lost it then. 😂

    • @paulpkae
      @paulpkae  Před 13 dny +20

      Haha! Brilliant! that made me laugh, thank you.

    • @jasonbender2459
      @jasonbender2459 Před 13 dny

      Your timer was 99.24% accurate. Well done. Your wife does not deserve you.

    • @jagmarc
      @jagmarc Před 13 dny +12

      @@dougtaylor7724 In the late 70s a colleague did a industrial controls dosing pump driver which used a simple RC timer with insane long period and being inexperienced, he didn't realise after it left assembly line no one in Functional Test wanted to wait a week ten days whatever it was. So the boss had to change the timer to something actually measurable and added a CMOS divider IC patched under PCB. We called the guy The 555 Kid after that.

    • @Mike-H_UK
      @Mike-H_UK Před 12 dny +5

      It is normally not a good idea to try and make very long delays (say greater than an hour) with a 555 directly because leakage in the capacitor tends to dominate the operation at such low charging & discharging currents, and the circuit is very sensitive to noise close to the comparator trip points. Adding a divider (as also suggested) makes operation much more dependable. Still, I had great fun s a kid learning these things for myself!!!

    • @Patrik6920
      @Patrik6920 Před 12 dny +1

      Fantastic...
      ya u can do all kinds of fun stuff with just a very few chips...

  • @Enderbro3300
    @Enderbro3300 Před 8 dny +33

    PLEASE I am BEGGING explain op amps like this. I feel like a BARELY understand them and this video made me feel like I can explain a 555 to a toddler!!

    • @paulpkae
      @paulpkae  Před 7 dny +17

      Hi. Yes, an Op-Amp explanation will be essential content for my General Electronics collection. It is on my long list to do.

    • @JamesHarr
      @JamesHarr Před 2 dny

      I think this is an excellent explanation of op amps, at least when they don't have any direct feedback loops. Op amps get weird (and interesting) when there is a feedback loop involved.
      I can't remember who explained it or even the specific circuit configuration, but when the feedback loop is involved, "the opamp will do as much as it can to equalize the input voltages" and that's what stuck with me.
      I look forward to Paul's explanation of opamps because I think it'll be even more clear than that.

    • @paulpkae
      @paulpkae  Před dnem +1

      @@JamesHarr challenge accepted 😲

    • @JohnDoe-lg8dr
      @JohnDoe-lg8dr Před dnem +1

      @@JamesHarrThe way that I learned op amps was that the op amp has variable gain internally and through magic will change the output voltage to make the two inputs equal. Then assuming the two equal inputs, you can find the desired output voltage. Slap on a capacitor or inductor and you now have an integrator or differentiator

  • @MrThedennisblack
    @MrThedennisblack Před 13 dny +61

    It’s exactly this kind of thing that we dreamed the internet would do for us - let people freely share their talents and knowledge with each other. Great explanation and video! Taking the time to briefly explain how the comparators worked and how the flip-flop worked is the exact kind of thing someone who doesn’t have natural teaching ability would have skipped completely.

    • @jaykoerner
      @jaykoerner Před 13 dny +3

      You just have to wade through the ai generated fake videos, completely lose your privacy to multiple gigantic corporations and be completely unsure if your even talking to a real person since 25% of Internet traffic is scammy bots and another 25 is supposed good bots

    • @paulpkae
      @paulpkae  Před 12 dny +6

      Thanks. I find sharing knowledge to be very rewarding. All your comments make the effort all worthwhile.

    • @arosnett
      @arosnett Před 9 dny

      Word!

  • @newmonengineering
    @newmonengineering Před 15 dny +134

    This is the best explained 555 timer video ever. I understand what it does already high level and how to figure out the numbers but I have never seen all the internals so completely discussed and stepped through like you did. Brilliant work! Absolutely love electronics so throughly explained with real world results like this. Keep it up! And thank you for a more indepth understanding.

    • @paulpkae
      @paulpkae  Před 15 dny +7

      Many thanks for your great comment.

    • @qlue7881
      @qlue7881 Před 13 dny +4

      I agree
      I've been doing electronics as a hobby since the late '80s and read many articles on this IC
      Today I understood, for the first time, why a 555 can't give perfectly symmetrical square waves

    • @paulpkae
      @paulpkae  Před 13 dny +4

      @@qlue7881 thanks for the comment.
      A video on how to achieve 50% (or higher) duty cycle is coming, if that's what you mean.

    • @paidaki11
      @paidaki11 Před 11 dny

      😊😊👍👍🙇🙇🙇🙇🙍🏾‍♂️❤😅❤❤😮

  • @katelikesrectangles
    @katelikesrectangles Před 3 dny +4

    this is the first time this chip has ever made sense to me, i never understood what it was doing inside. it was always explained to me as how to *use* it, not how it *works*. thank you so much!!

    • @paulpkae
      @paulpkae  Před 3 dny +1

      That's Great!
      More videos on the 555 coming, so make sure you Subscribe. 😀

    • @katelikesrectangles
      @katelikesrectangles Před 3 dny +1

      @@paulpkae oh this was an insta-subscribe for me, you've solved something that's been a mystery at the back of my mind since the '90s, where i felt like it was just my fault for not getting it. and i just never realised it could actually make sense

  • @brainforest88
    @brainforest88 Před 13 dny +19

    I am 61 an I am used the chip when I was 17. Didn‘t know this chip is still around. Nice!

    • @c1ph3rpunk
      @c1ph3rpunk Před 13 dny +5

      It’s still all over the place.

    • @paulpkae
      @paulpkae  Před 12 dny +6

      Still going strong and now manufactured by many companies and in various form factors, TTL, CMOS. There's even a dual 555, namely the 556.

    • @rfymf
      @rfymf Před 10 dny +3

      60 y. o. here... same.
      Designed and built a digital clock around it at 15. With the additional 74something nand gate ttl chips, it
      had the accuracy of 1 min per hour,
      and drained C batteries in a couple of hours...

    • @numbr6
      @numbr6 Před 8 dny

      Of course it is still around! I've got a bunch of them in my drawer of digital chips, along with my TTL and CMOS series chips. I first started tinkering with this chip from the TTL Cookbook, author Forrest Mims published by Tandy/Radio Shack. I've still got my copy of that book along with a bunch of chip pack cardboard "data sheets" stapled to the inside cover of of this book. Back in the 70s/80s, getting data on chips was hard. You kept those precious package data backs, and was very familiar with the Reader's Guide to Periodic Literature, and microfiche film at libraries to get data. Now it is just a Google search away, or a visit to Digikey! Technology has made some things easier.

    • @ezemeza1363
      @ezemeza1363 Před 8 dny +1

      I am 31 and getting started into electronics. This chip is very useful and cheaper than programming and Arduino

  • @karlsangree4679
    @karlsangree4679 Před 14 dny +36

    This might well be the best explanation of an electronic component I have ever seen. This is "Electronics for Dummies" which is exactly what I need. I just went to his main page hoping and praying that he had a complete "Learning Electronics" tutorial but alas...😥

    • @robr4662
      @robr4662 Před 13 dny +3

      More like electronics for someone who is casually familiar with how electricity works. If someone was truely uneducated about any electrical theory, this video would be useless. That being said, this video explaining a 555 timer is better than any other video I have seen on the subject.

    • @paulpkae
      @paulpkae  Před 13 dny +8

      Hi thanks for the comment. My channel is quite new and small at the moment, but I have much bigger plans for it. and any more videos will be coming.
      Please make sure you Subscribe if you want to support. Thank you.

    • @paulpkae
      @paulpkae  Před 13 dny

      @@robr4662 thank you.

    • @JohnVance
      @JohnVance Před 12 dny

      @@paulpkaeSubscribed, thank you!!

  • @joedfazio
    @joedfazio Před 8 hodinami +1

    I designed circuits using 555 timers back in the late 80’s. Thanks for the memories! BTW the 556 is twice the fun 😊

    • @paulpkae
      @paulpkae  Před 7 hodinami

      Thanks, glad you enjoyed it.

  • @techtopics5782
    @techtopics5782 Před 10 dny +6

    this is honestly the best explanation I have seen on the 555 and its operation. The explanation + visuals + calculations + breadboard + scope with comparison = awesome. I like that math!

  • @jeffspaulding9834
    @jeffspaulding9834 Před 11 dny +10

    People say it wasn't named after the 5K resistors because that's what the inventor of the 555 said in an interview. It was named by a marketing fellow who thought "555" was catchy.
    Brilliant video, BTW.

    • @paulpkae
      @paulpkae  Před 11 dny +4

      Yes, I have heard that too, but for me it seems too co-incidental.
      Thanks for the comment.

    • @matousejem
      @matousejem Před 6 dny +2

      Maybe the marketing fellow saw the schema and got the idea.

  • @dustinduncan2444
    @dustinduncan2444 Před 11 dny +4

    Brilliant video. I was surprised that I could watch this length of video on the venerable 555 and not find my mind wandering. It's a testament to the ability to teach and keep people engaged in the content.
    I really appreciate breaking down the pins and how they are related without just glossing over why a given pin is connected to a specific point in the circuit. The color coding of the internal and external voltages along with the logic level changes definitely made it easier to follow what was going on.
    Bonus points for building up the bench demo from a couple LEDs to the oscilloscope traces that took the diagrams from a simulation to the real world.

    • @paulpkae
      @paulpkae  Před 11 dny

      Thanks for your comment. It took quite some effort to put this together to be honest, but I am please with the outcome, especially all the comments like yours. Please remember to Subscribe, if not already. 😁

  • @TheRandomDave
    @TheRandomDave Před 12 dny +2

    Adding my voice to all the others...absolutely brilliant job explaining and demonstrating the 555 timer.

  • @athousandprojects
    @athousandprojects Před 12 dny +6

    I think this is the best video about how a 555 works I've ever seen.

  • @tlum4081
    @tlum4081 Před 5 dny +1

    i once worked for a small company whose main "electrical engineer" only knew relay ladder logic. I designed a simple 555 circuit operating in a sequence to signal solenoid air valves to open to blow dust from a multiple dust bag system into the waste bin. Worked like a champ. They thought it was the cat's meow.

  • @KatyInesSB
    @KatyInesSB Před 15 dny +15

    Never see a video about 555 well explain. Amazing. Keep me on screen to understand this chip, and how they work.

  • @billdevany3303
    @billdevany3303 Před 13 dny +11

    your addition of the color gradients was a real game changer for me. thanks for this. Well done!

    • @paulpkae
      @paulpkae  Před 13 dny +3

      Thanks. An additional bit of effort can make a lot of difference.

  • @MarkALong64
    @MarkALong64 Před 13 dny +3

    That was an enjoyable trip down memory lane :) I once met a very excited chapin the gents of a Southampton pub who had designed the timer circuit for the hot air hand dryer using an NE556 and for some reason, he really wanted to explain the circuit to anyone who would listen.

    • @paulpkae
      @paulpkae  Před 13 dny

      From my experience, those hand dryers must have the wrong size capacitors in them then . 😆

  • @markramsell454
    @markramsell454 Před 2 dny +1

    I used one of these for a 1Mhz clock on a 6502 board I made. It worked just fine. Nice description, very thorough.

  • @AvastAntiPony9445
    @AvastAntiPony9445 Před 6 dny +1

    Ok now it makes tenfold more sense to me why it's called a 555, genuine surprised i haven't heard anyone explain it till now, and that everyone calls it a "timer" chip.

  • @gedtoon6451
    @gedtoon6451 Před 15 dny +7

    Great in-depth video on the 555 in astable mode. A follow up video could cover monostable mode. This would explain why the designer of the device didn't just connect trigger and threshold together inside the chip.

    • @paulpkae
      @paulpkae  Před 15 dny +3

      Thanks for your comment. I do intend doing some follow up videos to this.
      My very next video however is going to be a review of a nifty digital microscope.

  • @arthurmoore9488
    @arthurmoore9488 Před 8 dny +2

    Commenting before I watch the video. Bet it's going to be how the 555 is really a dual comparator with some nifty tricks. The "timer" bit comes from how long it takes to charge/discharge a capacitor to a specific value. It's been years since I've worked with one though, so this is pure memory and speculation.
    I should also note that using similar circuits, you can measure voltage by using it as a voltage to frequency converter, then measuring the frequency. With the beautiful part being the final measurement circuitry can be optically isolated!

  • @javiermitchell7073
    @javiermitchell7073 Před 12 dny +4

    Really well explained. This must have been one of the most " mysterious" circuits I came across when I was a youngster!

    • @paulpkae
      @paulpkae  Před 12 dny

      Thanks. Glad you enjoyed.

  • @remi3741
    @remi3741 Před 13 dny +6

    like in the comments already i to never saw a video so well explaned about an electronic divice. fantastic. i wish more people would do it like this on more components or cicuits. its fantastic for biginners and hobby. thank u so much.

    • @paulpkae
      @paulpkae  Před 13 dny

      thanks so much for your comment. I'm glad you found it useful.

  • @user-rl5zj7np4e
    @user-rl5zj7np4e Před 9 dny +3

    A Masterpiece for electronics engineering teaching. Bravo!!

  • @tedbastwock3810
    @tedbastwock3810 Před 15 dny +10

    What an amazing video. I have watched probably 2 dozen 555 videos recently, none are better than this. Visuals are great. Was also a very good explanation. You managed to make an entertaining and informative video on something that already has a lot of videos on it but with a unique and useful twist. E.g. I never took the time to figure out exactly how the astable mode works, and I'm very glad you walked me through it here. I haven't seen anyone else do that, and I'm glad you did. I cant wait to see see your other 555 videos that you mentioned at the end. Thanks for sharing.

    • @paulpkae
      @paulpkae  Před 14 dny +5

      Many thanks for your comment. More videos coming......

  • @user-fed-yum
    @user-fed-yum Před 6 dny +1

    I remember using the 555 on a game that I made, forty years ago, to win my school science competition. Amazing how long they (and me) have been around.

  • @GrandsonofKong
    @GrandsonofKong Před 4 dny +1

    Great description and video!
    555 was developed by Signetics founded by some former Fairchild Semiconductor Engineers (like Intel was). I worked at National Semiconductor (just around the corner from the Signetics Plant) and we called it the "Triple Nickel" at least in our department(Test Engineering) when NSC decided to second source the 555. Still have a Signetics Apps Book on my bookshelf and a very useful chip when the only option was a bunch of TTL Logic to do timing when you could get away with only a few external components back in the day.

    • @paulpkae
      @paulpkae  Před 4 dny

      Thanks for the comment and your interesting history insight.

  • @Mitch3D
    @Mitch3D Před 13 dny +4

    Thank you for this explanation and demo! I only really learned how to do microcontrollers with electronics so finding out other uses for simpler components is useful. One use for the 555, instead of a capacitor and voltage divider, you could use a thermistor to vary the threshold voltage based on temperature and tie the output to a relay to turn on a heater, you have made a simple bang-bang control loop.

  • @YodaWhat
    @YodaWhat Před 9 dny +4

    It is worth mentioning that the Control Voltage *pin, #5, is also known as the Pulse Width Modulation pin.* I have had great fun playing with that function, even turning a CMOS 555 into a Digitial Mode audio amplifier with pin 5 as the audio input! A couple of extra components are needed beyond the usual few for a simple timer: an external transistor to make the duty cycle 50% ON and 50% OFF, plus an inductor to knock out the high frequency elements of the output signal, and a small capacitor on pin 5 to give DC isolation from the audio source. I set the oscillation frequency to be 2 MHz, which is only possible with the CMOS 555. That meant each wave of the audio input was _in effect_ 'sampled' 100 times (for 20 kHz audio), and 100,000 times (for 20 Hz audio), giving high fidelity to the *_implicit_** A-to-D conversion* and to the audio output. 🙂

    • @paulpkae
      @paulpkae  Před 8 dny

      Thanks for sharing your knowledge.

  • @fshieldsii
    @fshieldsii Před 13 dny +3

    First time you've shown up in my feed. Your explanations and presentations are so good that I've subscribed!

    • @paulpkae
      @paulpkae  Před 13 dny

      Brilliant! Thanks for subscribing.

  • @BoukeGroenescheij
    @BoukeGroenescheij Před 7 dny +1

    Wauw, even though there are over 300 reactions telling you this is the best explanation ever seen, I'll just add another one. What a great explanation, one of the best 30 minutes on CZcams :-). Thank you for sharing, I've subscribed!

    • @paulpkae
      @paulpkae  Před 7 dny

      Great! Thanks for watching, the comment and even more for Subscribing.

  • @robandsharonseddon-smith5216

    Loved it. Took me back to my teens in the 80s. I never understood it then tho. More like this please

    • @paulpkae
      @paulpkae  Před 13 dny +1

      Thanks for the comment. More videos coming....

  • @josephthibeault4843
    @josephthibeault4843 Před 3 dny +1

    I love the 555 many applections think out side the box!

  • @RexxSchneider
    @RexxSchneider Před 10 dny +2

    The NE555 bipolar timer has an output stage that produces a significant spike of current as it switches, and that can cause problems both for itself and for nearby ics as it tends to produce a negative spike on the supply lines. It is pretty essential to place a ceramic 100nF capacitor across the supply pins, close to the ic to suppress that. It's not so necessary if a CMOS 555 is used.
    It doesn't matter for the astable circuit you show, but for use as a monostable, or other circuits, it's worth knowing that the TRIG input (pin 2) overrides the THRES input (pin 6), which means that if the TRIG input is held low, the output goes high and the THRES input cannot reset that by being taken high.

  • @peterwadham7965
    @peterwadham7965 Před 9 dny +1

    I agree this is one of the best explained 555 timers vides that I have seen, I remember looking at the timer at college and it seem difficult to understand as we had was the RS data sheet written by electronic professors

    • @paulpkae
      @paulpkae  Před 8 dny

      Thanks. Brilliant comment, encourages me to produce more....

  • @alexcrouse
    @alexcrouse Před 12 dny +3

    I once found a single chip circuit board controlling the water level in a tank. Very very old system. I asked the maintenance grey beard why they had a microcontroller instead of a PLC. He laughed. "That's a 555!"
    With some resistor magic and a variable resistor on a float, they set the low level to report 3v, and the high level to 6v, and the 555 triggered the fill valve.

    • @paulpkae
      @paulpkae  Před 12 dny +3

      Thanks for sharing. I'm sure there's been millions of different 555 implementation types over the years.

  • @LonnonFoster
    @LonnonFoster Před 11 dny +2

    Brilliant explanation! It's not often I find any material that blends theory and practice so well. Your shifts between diagram, breadboard, and oscilloscope are beautifully timed in the video; this is the clearest I've ever seen a 555's operation described. Thanks for taking the time to craft such an excellent video!

    • @paulpkae
      @paulpkae  Před 11 dny

      Glad you enjoyed and thanks for the great comment.

  • @Electrodoc1968
    @Electrodoc1968 Před 12 dny +1

    Nice to hear this explanation lives on..
    PNP & NPN Was one of the first things I was taught when I was in a YTS T.V. Engineer training apprentice. ~1986 +
    Point iN Please & Not Pointing iN.
    Project building hobby led to a self taught knowledge of the voltage polarity workings for basic switch amplification. ie.
    PNP = A Positive on the Emitter then the base should be held Negative 0v to switch the collector through to the Positive.
    NPN = A Negative on the Emitter then the base should be held Positive to switch the collector through to the Negative.
    Basic relay type stuff.
    But also a general rule in amplifiers but that gets more datasheet reliant for HFE values etc.
    Cheers.

  • @spark_coder
    @spark_coder Před 11 dny +1

    This is by far one of the best explanations for an electronic component that I've ever seen.
    Your intro burst my ears (I was wearing earphones) but it was totally worth it for how good this video was and how well I was able to understand what you were teaching.
    Thank you for this video ❤

    • @paulpkae
      @paulpkae  Před 11 dny +1

      Thanks. Yes a few people have mentioned the intro volume. I had tweaked by OBS settings prior to recording to try and improve the clarity and forgot to normalise my intro recording.
      Other than that, I'm glad you made your way through it and found it of use.

  • @connecticutaggie
    @connecticutaggie Před 4 dny +1

    Nice explanation of how a 555 works.

  • @Ancipital_
    @Ancipital_ Před 12 dny +1

    Thanks, I will need to watch this a couple more times to completely understand it. I'm a bit new to elecronics!

    • @paulpkae
      @paulpkae  Před 12 dny +1

      @@Ancipital_ thanks. And yes, watch a couple of times or more and it will sink in.

  • @MrCapacitator
    @MrCapacitator Před 12 dny +1

    Best 555 explanation I've seen 👍

    • @paulpkae
      @paulpkae  Před 12 dny

      Wow, thanks! Make sure you Subscribe, there will be more coming.

  • @donkeymedic
    @donkeymedic Před 11 dny +1

    This is by far the best explanation of the 555. I struggled to understand it , but this made it clear.

    • @paulpkae
      @paulpkae  Před 11 dny

      Thanks for the comment, much appreciated.

  • @thb40
    @thb40 Před 3 dny +1

    excellent explanation of how the 555 works.

  • @gregf9160
    @gregf9160 Před 2 dny

    My father, an electronics engineer said "PNP = Piss _in_ Pot (arrow points in) NPN = _No_ Piss in Pot (arrow points out)" when I was learning this stuff as a kid.

  • @CraigsWorkshop
    @CraigsWorkshop Před 5 dny +1

    Thanks for making this video! I had 3/4 of an idea how these chips worked, but now it's crystal clear. You are a great teacher.
    I hope you keep making these vids. Cheers!

    • @paulpkae
      @paulpkae  Před 5 dny

      Thanks for watching and the comment, glad you found it useful. Yes more videos are coming, so make sure you Subscribe too 😁

  • @jupa7166
    @jupa7166 Před 6 dny +1

    It is a brilliant chip design, sooooo versatile! I like it very much. I also like LM10 - look it up, the datasheet just oozes with ideas.

  • @MKeuning01
    @MKeuning01 Před 12 dny +1

    Absolutely wonderful explanation of the 555. Thank you.

    • @paulpkae
      @paulpkae  Před 12 dny

      Thanks. Glad you enjoyed.

  • @jensschroder8214
    @jensschroder8214 Před 14 dny +3

    On the NE555, the reset input always overwrites the set input.
    On the B555, the set input overwrites the reset input. The replica wasn't quite perfect.
    This only happens when pin 2 is low and pin 6 is high at the same time.
    So comparator 1 and 2 are high at the same time.
    But for most circuits it makes no difference, because pin 2 and 6 are mostly connected.
    Therefore both comparators are different or both low.
    With the B555 the /Q output of the flip-flop is not used but the Q output.
    That's why set is stronger than reset. Accordingly, the output driver is not inverting.

  • @hankcohen3419
    @hankcohen3419 Před 13 dny +1

    Brilliant! It makes me admire the engineer who thought this up in the early days of digital electronics. Also confirms that all electronics is analog.

    • @paulpkae
      @paulpkae  Před 13 dny +1

      Thanks for the comment.
      Yes all electronics can be said to be analogue. A 1 or 0 is only a voltage threshold at the end of the day.
      Just to add, from my experience, everything also always boils down to Ohms law if you drill down enough.

  • @GregOnSummit
    @GregOnSummit Před 8 dny +1

    Man ... this is what I like. Easy to understand with a nice example on what you did. Subscribed 👍

  • @dennisbuns
    @dennisbuns Před 10 dny +1

    Enjoyed the whole video. I had learned about 555 before but this is much clearer and easier to remember. Keep doing this please. Cheers.

  • @JohnVance
    @JohnVance Před 12 dny +1

    I finished Ben Eater's 8-bit CPU and wanted an even more in-depth explanation for the timer, and your video was fantastic. Also had no idea those jumpered resistor network boards existed!

    • @paulpkae
      @paulpkae  Před 12 dny +2

      Wow, that must have been a rewarding project to have completed. I have watched Ben's videos too and fascinated in seeing the building blocks of a computer assembled and running on breadboards.

  • @KonstantinDeak
    @KonstantinDeak Před 2 dny

    First video I've seen of yours and its great. Very clean, no blurry camera stuff, WELL explained, excellent format of diagrams and bench testing. Liked and Subscribed!

  • @shokdj1
    @shokdj1 Před 10 dny +1

    Well explained. I can see why these things were so handy

  • @SusanAmberBruce
    @SusanAmberBruce Před 16 dny +3

    You put a lot of effort into this video, thanks, I hope you are not discouraged by the lack of interest

    • @paulpkae
      @paulpkae  Před 15 dny +3

      Thanks. It was indeed a lot of effort. I just hope people enjoy the results. Thanks again for your comments, much appreciated.

    • @tedbastwock3810
      @tedbastwock3810 Před 15 dny +3

      Lack of interest? You commented 3 hours after it was published. Give it time, Im sure this vid will get a lot of views .. or at least it should, considering how good it is.

    • @esra_erimez
      @esra_erimez Před 13 dny

      @@tedbastwock3810 I could not have said it better myself. This is by far the best explanation. I think this video will go viral

  • @mazeppa8818
    @mazeppa8818 Před 9 dny +1

    Thank you for this educational video! Really like the idea of colour-coding the voltage values!

    • @paulpkae
      @paulpkae  Před 8 dny

      Thanks. Yes colour code t represent the voltage (or potential) I think helps a lot. Pleased you found it useful.

  • @int2str
    @int2str Před 15 dny +4

    Wonderful video - thank you! Best explanation of a 555 I've ever seen. Really helpful!

    • @paulpkae
      @paulpkae  Před 15 dny

      Thanks, much appreciated.

  • @msmeyersmd8
    @msmeyersmd8 Před 12 dny +1

    For me, I get nostalgia remembering the late 1970s starting in college studying engineering physics that included using an analog computer (shoved in a corner storeroom) and some basic biomedical electric engineering design. Isolating the patient from any mains exposure.
    In the late 1990s, much to my wife's disbelief, I would study/stare at high fidelity analog amplifier circuit diagrams. From vintage tube amps to state-of-art solid state stereo amps.
    Following the various feedback circuits used to eliminate harmonic distortions.
    Why? I'm not sure. I had extra time on my hands and it was so relaxing.
    Just like watching this video.
    "555 timer" circuits used to be in the many electrical/electronic hobby magazines years ago.
    Magazines.
    Gone the way of phonographs, magnetic tape, CDs, laser discs, DVDs, etc.
    My 2003 Toyota had an electric motor extension for the radio antenna that was broken off in the car wash. It ran every time I turned the car on or off. I thought I could just pull the fuse.
    It was fused, all right. But on the same circuit as 10 other totally unrelated and multiple necessary things.
    Probably through some special IC or microprocessor?
    I couldn't find a "wiring diagram" on the internet and the dealer will not give me a copy.
    Actually, the dealer has no circuit diagram in the classic meaning of the words.
    Just broken up functional portions on their computers.
    I finally had to pull the power wire by accessing it through the wheel well above the tire.
    I miss the 20th Century.
    Keep the videos coming. I'm sure I'll enjoy them.

    • @paulpkae
      @paulpkae  Před 12 dny +1

      Thanks.
      Much of the old fashioned approach of trying to fix stuff yourself has sadly gone. But there is a new era of developers, building entirely new and exciting electronics devices out there. I'm convinced the emergence of low cost micro-controllers has fuelled a mass increase in young interest.

  • @shaheeap
    @shaheeap Před 3 dny +1

    Its very very informative , back in days i used to wonder how the 555 ic worked.
    But the thumbnail is misleading

    • @paulpkae
      @paulpkae  Před 3 dny

      Thanks for the comment.
      Sorry if this confused you. The thumbnail text is the main tool we have to attract views and is somewhat tongue in cheek and a bit controversial I suppose. But, you have to watch the video to understand what I really meant by the statement.
      It's only a timer if you add components around it to become a timer. The 555 is a far more versatile device and can be put to many other uses too. There are more videos to follow.....

  • @robf9931
    @robf9931 Před 20 hodinami +1

    Brilliant explanation.

  • @heisen6376
    @heisen6376 Před 11 dny +1

    Liked and Recommended, I'll do whatever I can to see this channel grow. ✌

  • @grahamlewis6777
    @grahamlewis6777 Před 5 dny +1

    Great video, thanks for all the effort you put in to create this with all the graphics too. Great work :)

    • @paulpkae
      @paulpkae  Před 5 dny

      Thanks for the comment, much appreciated.

  • @planktonfun1
    @planktonfun1 Před 13 dny +1

    I never had the tools to see this, pretty nice to know!

  • @rogueninja1685
    @rogueninja1685 Před 2 dny

    Until this video, I always thought the timing mechanism was a constant somehow and explanations of the 555 never pointed out the required external components to make it work. Capacitance and resistance was all it ever was and now I feel like I have a good handle on the whole thing. It's amazing how many blanks this single video filled in, particularly the noise capacitor

    • @paulpkae
      @paulpkae  Před dnem

      Great! Glad this video has helped fill in the gaps.

  • @cbm_doomworld
    @cbm_doomworld Před 6 dny +1

    thanks for a really interesting video. I look forward to seeing more on the 555 and other components. I amcurrently building my own little electronics workspace where I can build stuff like this.

    • @paulpkae
      @paulpkae  Před 6 dny +1

      Thanks, glad you enjoyed and please your starting your own little electronics workshop.

  • @HeadCodeMonkey82
    @HeadCodeMonkey82 Před 15 dny +2

    Great explanation, you made it really clear and easy to understand

    • @paulpkae
      @paulpkae  Před 15 dny

      Thanks. Glad you enjoyed.

  • @zalida100
    @zalida100 Před 15 dny +2

    Excellent vid.
    Clear explanation etc. Very enjoyable. 1st class stuff. Thanks for your efforts.

    • @paulpkae
      @paulpkae  Před 15 dny

      Glad you enjoyed it and thanks for the comment.

  • @muhammadhussain7976
    @muhammadhussain7976 Před 13 dny +2

    Very impressive demonstration and explanation!

  • @tincanpete
    @tincanpete Před 10 dny +1

    Excellent explanation and diagrams, thank you!

  • @dacodemonk
    @dacodemonk Před 13 dny +1

    After all these years... I finally understand these things! Thanks a ton! You just got a sub from me!

  • @GenericCat
    @GenericCat Před 10 dny +1

    wow the 555 is a bit latch! I have it up on a breadboard with multimeter leads and some pull up resistor on the trigger pin so it defaults to 0 and was following along with the graphics. that's super cool :D

    • @paulpkae
      @paulpkae  Před 10 dny +1

      @@GenericCat brilliant, glad you enjoyed.

  • @YarGnawh
    @YarGnawh Před 12 dny +2

    instant subscribe. the best explanation video of the 555 ever.

  • @CoupleofBunkies
    @CoupleofBunkies Před 12 dny +1

    555 timer is real handy thanks for the video

    • @paulpkae
      @paulpkae  Před 11 dny

      Thanks for the comment and watching. Glad you found it useful.

  • @jjones503
    @jjones503 Před 13 dny +1

    Brilliant explanation. Thank you. Subbed!

    • @paulpkae
      @paulpkae  Před 13 dny

      Many thanks. Glad you Subscribed, welcome to our growing community of electronics enthusiasts, hobbyists and professionals.

  • @MellexLabs
    @MellexLabs Před 9 dny +1

    This was a fantastic video... the presentation is... chefs kiss 👌

    • @paulpkae
      @paulpkae  Před 8 dny

      Thanks, glad you liked it.

  • @accidentalengineering
    @accidentalengineering Před 10 dny +2

    "Might be a timer..."
    "IT'S NOT A TIMAH, NOT A TIMAH AT ALL!"

  • @chronobot2001
    @chronobot2001 Před 10 dny +1

    Nicely done.
    Very clear.

  • @sky173
    @sky173 Před 2 dny

    Great video. I've been using them since the early 80's It's hard to believe it's been around for so long. Thanks for sharing. PS> might want to reduce that intro volume a tad.

  • @AndrewElgert
    @AndrewElgert Před 13 dny +7

    NPN = "Never Points iN" is a brilliant mnemonic

    • @evangiles4403
      @evangiles4403 Před 13 dny

      And for a PNP it's Points iN Permanently

    • @nordicexile7378
      @nordicexile7378 Před 11 dny +1

      It's been around for a long time. My father taught me NPN and PNP going on close to 60 years ago now.
      He also taught me the resistor colour code... (NSFW version)

  • @leonerduk
    @leonerduk Před 14 dny +2

    Ahh, a man of class. I see a UT61E here ;)

    • @paulpkae
      @paulpkae  Před 14 dny +1

      Indeed. And, a set of Probe Masters.

  • @leonardorissato
    @leonardorissato Před 14 dny +2

    Really well explained!! I hope you get many more subscribers

    • @paulpkae
      @paulpkae  Před 14 dny

      Thanks. and yes me too, although the count is gradually creeping up. The %views vs Subscribe is VERY low, but I believe that's quite normal.

  • @Mark-ce9xh
    @Mark-ce9xh Před 11 dny +1

    Awesome video! Thank you!

    • @paulpkae
      @paulpkae  Před 11 dny

      Thanks for watching and thanks for the great comment.

  • @oscargraveland
    @oscargraveland Před 13 dny +1

    Brilliant how the switching points are at 1/3 and 2/3 of the voltage range respectively, making the charge and discharge relatively linear.
    Imagine how inconsistent the timing would be if the switching points where near ground and VCC.

    • @paulpkae
      @paulpkae  Před 13 dny

      Yes, although the RC time constant remains the same throughout the charge/discharge phase, the shallower curve region as the charge approaches the +V or -V potentials, would probably cause some erratic behaviour.

  • @johnfox4691
    @johnfox4691 Před 13 dny +1

    Very well explained. Thanks.

  • @subtlethingsinlife
    @subtlethingsinlife Před 10 dny +1

    Without doubt the best explanation

    • @paulpkae
      @paulpkae  Před 8 dny

      Thanks so much, glad you liked it.

  • @fdavpach
    @fdavpach Před 12 dny +1

    What an awesome video, I always thought of the 555 as being a fancy flip flop, now it all makes sense, 555 is just a 1/3-2/3 hysteresis circuit.
    One of my favorite funny projects with 2 555s or a 556 is the atari punk, an atari like sound generator, maybe that can be an interesting explanation later if you continue with the 555 series?

    • @paulpkae
      @paulpkae  Před 12 dny

      Thanks for the comment. More 555 videos will be coming.

  • @hoshedar05
    @hoshedar05 Před 2 dny

    Beautifully explained. Thankyou

  • @ethanjohnston8644
    @ethanjohnston8644 Před 15 dny +2

    this is super informative. people are lucky to get this depth of understanding since school will likely not teach this. Could you do a video like this but covering LDOs?

  • @SilverC
    @SilverC Před 13 dny +1

    Phenomenal video!

    • @paulpkae
      @paulpkae  Před 13 dny

      Thanks so much. Comments like this make all the effort worthwhile.

  • @Soloist1983
    @Soloist1983 Před 13 dny +2

    Loved the video but I would have hired that Schwarzenegger voice impersonator from insta and had him say "It's not a timah" in the opening, a la Kindergarten Cop 😆😆

  • @mcsroberto1
    @mcsroberto1 Před 12 dny +1

    Thank you for your great explanation 👍

  • @actually_it_is_rocket_science

    Ok a minute in and you got a new sub.

  • @alphalunamare
    @alphalunamare Před 7 dny +1

    Not being snotty but I understood all of that. Having worked for many years with jobbing hardware engineers I'd be amazed if they had the intelectual capacity to have understood this. I am a Software Engineer unfortunately ;-)

  • @peterwilhelmsson4168
    @peterwilhelmsson4168 Před 13 dny +1

    This video is fantastic! Thank you so much! 🎉🎉🎉

    • @paulpkae
      @paulpkae  Před 13 dny +1

      Thanks for the comment. Please make sure you Subscribe and help the channel continue.

  • @Astronomator
    @Astronomator Před 3 dny +1

    Thank you for this marvelous video.

  • @petevenuti7355
    @petevenuti7355 Před 12 dny +1

    You earned a subscriber!
    Hope you get many more!!

    • @paulpkae
      @paulpkae  Před 11 dny

      Brilliant! Thanks for watching and especially for Subscribing too, it makes a difference.

  • @kraftaculousgreekgodofcraf1113

    Hey.. woah… wooooaaaahhh… 1971 is not very old. Thank you very much. A lot of good kids were born in 1971 that aren’t very old… 😤 including myself. 😂
    Great video by the way thank you I’m a beginner at 53 at electronics so it’s good to have things explained so well

    • @paulpkae
      @paulpkae  Před 13 dny +1

      Haha. I was not born in 1971.
      I'm actually from the 60's !!!!! eek!

  • @mechanoid5739
    @mechanoid5739 Před 13 dny +1

    Best explination ever! Thanks😁

    • @paulpkae
      @paulpkae  Před 13 dny

      Thanks. Glad you enjoyed. Hope you have Subscribed too?

  • @sorh
    @sorh Před 13 dny +1

    What a great video, thank you sir. 👏