I’ve watched four different explanations on the NE555 internal workings and so far this one has made the most sense. A bit fast in places but it’s a video, I can go back and watch it again and try to pick up what I’ve missed. Thank you so much for your time and expertise on the subject matter and for “dumbing it down” in plain words and diagrams so that more people can enjoy electronics.
This is one of the best presentations for working of the 555. We've used the 556 as astable and monostable together to produce a PWM signal for a Boost Converter, 12v t0 48v DC at St. Joseph's Research, BLR, IN.
Very nice tutorial, especially given it can be configured 3 major ways. I am a math guy that hobbies in electronics and studied the 555 a few months back. It was nice that your video mentioned that the integrated flip flop actually used only one of the outputs which is a detail that often is overlooked in other explanations. I ended up building an astable Multivibrator so that I could put out a weak signal in the AM broadcast band spectrum in order to test reception capacity on regenerative radio receivers that I assemble from parts at hand. It worked, barely. By barely I mean that high a frequency was kind of pushing my luck. Without filters it was also broadcasting everywhere much like a skipping stone across a pond.
How did u manage to do that how could you send out a wave using the 555 timer never mind I am a late bloomer my brain would take too much time to process but I would very much love an explanation
@@akashsunil7464 Its been a year or two, but as I remember I set the IC555 to the highest frequency that I could get it to oscillate at using the configuration shown on the data sheet. This was a matter of selecting as I remember resistors at specific pinouts. The frequency that I was able to get was around 500KHz. I then added an audio transformer to the endeavor so as to inject audio such as a tone, into the signal it was generating thru being allowed to oscillate. It was a lousy transmitter but it did put out enough mili-watts to be heard by a radio in the next room. It also had a square wave & produced harmonics all over the place. Its kind of funny in that back then I spent a day or two understanding the entire innards of the chip & what could be done with it. I barely remember any of the details anymore. None the less its better suited for turning your car's dome light of than using as a low power transmitter
I have seen so many videos about 555 in my native language but somehow they were confusing until i found this video simple and understandable even with a foreign language description
I wish we’d had resources like this when I was studying Electronic Engineering and building 555 circuits back in 1981! Such a great little timer, I built all kinds of alarms and flashing lights etc with them, but getting across all of the concepts etc was much more of a dry subject than it is today. I really like how simple and clear you made this for people starting out. Great stuff.
@@larrybud I'm 68. In the 70's they had mainframe computers behind glass doors in my college that ran tape. I thought writing instructions with zeros and ones was tedious. In 2008 I discovered I could control the behavior of motors by writing instructions. I was hooked and realized I had wasted my college career.
@@larrybud I still have some of those overpriced and dull books on the shelf lol. There was very little choice of content at all and most of it was presented in a way that made things more difficult than they needed to be. I don't know about you but I had a mix of some very good lecturers and some that were just terrible. Luckily I worked with some very helpful people while studying and was given projects that helped me learn and keep it interesting.
@@awaitingthetrumpetcall4529 In the early 80s I was initially more interested in electronics (and cars/motorcycles lol) than computing but got exposed to personal computers as well as the mainframes in the telco space. In the early days most of the electronic projects that I built for myself were for cars and bikes - I built a full car computer that monitored fuel consumption and distance etc, car and bike alarms, electronic central locking. I got into computing outside of work in a big way when the Amiga 1000 came out (prior to that had a z80 machine at home), but the Amiga was a game changer. It could be programmed to play music properly and could display quality photos - something that the IBM based business machines just couldn't do.
A good 50 years ago I started in electronics making my first medium wave receiver with an ECC82 valve. A year or two later, in 1972 the 555 was introduced and I've been dabbling with it ever since. Thank you Hans Camenzind ! Nice video BTW 👍.
My understanding for electrical concepts is not enough yet, but I loved how every pin was explained in detail. Hopefully I can comeback to this video to understand it. Thank you for such a descriptive video.
First time I've seen an understandable description of this chip. Thank you. By the way, I have a friend who says he's bistable, but practicing as monostable because it's just easier to live that way. All good wishes!
Wow, I wish I had a teacher like you, decades ago. It could've been career changing. Nice to learn the basics. Kids these days leap jump straight to a raspberry Pi and they find basics, pointless.
Great video. I’d also add that the rs latch is basically an electrical version of a mechanical toggle switch. But unlike the mechanical toggle switch the rs latch has 2 dedicated physical quantity inputs (either high or low) to change the state of the output. The mechanical toggle switch has a single algebraic input consisting of the application of a + force or a - force to change states. This 555 timer is an example of an application of the rs latch thru the use of the 2 comparators assigned to each of the 2 physical quantity rs latch dedicated inputs. Such a configuration can be used for automatic temperature control as set with a thermostat . And so that’s potentially an additional practical implication (besides an oscillator) of an rs latch configured with a couple of comparators to change states to turn furnace on or off to reject heat loss effects thru the walls of a heated building. Unlike the oscillator both the period and duty cycle of the 555 output behavior in the furnace example will change depending on outside temperature.
If I’m correct, Pin # 4 is the Base of a PNP transistor which Is set Hight turning the transistor OFF, and when the switch is pressed the base is grounded, an therefore the PNP transistor should go ON. Thank you
So excellent in explaining!!Coming upon a female electronics engineer made this more exciting to learn. Good for you, indeed! I thoroughly enjoyed this!!
Yup, that didn't even bump my head as it went over. Her well executed explanation still left me just as confused as whence I came. I just need a 3 second delay on a 12 volt circuit.
I allready use this when i made an inverter 12volt dc to 220 v ac since 1995, i was happy that it's clear explanation thank karen, thank yuo very much....
Great Graphics!!! Contrast and highlighting is properly used without unnecessary distractions. The “ how it works” part is fascillitated by Karen, who shows both Teaching Experience and Knowledge of the subject. As a Presenter, she is comparable to Liliana de Castro, who does Group Theory for Socratica. All pins were covered without the dismissive “ this pin is seldom used” . I hope to see Karen in more videos.
6:30 "If pin 4 is ever grounded, going low, the transistor is turned OFF." Actually, it's the opposite because this is a PNP transistor, so it is held OFF while pin 4 is high, and it turns ON when pin 4, its base, goes low.
Superb, Milady! I always have some..10 or 15 of them in mi parts bin. I had even made some NCG control boxes for cars and there They are, working almost 10 years later! I had a book (ugly, fat,big book) that I can't find nowadays, about the 555, and it stated somewhere; "555's are like rice....there are more than 1000 recipes wit them!". Thanks a lot for your videos! And "hi.5!" from Argentina!
Fine explanation. Had watched many tutorials but this was the best. Thank you so much. A small point. In your next videos please try to make a little bit slow in words. As some of my friends felt so. Then persons who are not very conversant in English will enjoy it more
Very useful We call it Triple 5 (timer), in my area in Australia We also say 5k (for the resistor, five Kay), We are already metric so we understand 1K etc
This is the first video I watched from you and I loved it. I used the 555 many times over decades but never understood it in such depth. Very useful and helps with troubleshooting circuit design. One thing I may not be understanding is that when you said that when pin 4 is grounded, the transistor turns off. Being a PNP, shouldn't it come ON when the base is brought to ground? Maybe i misunderstood?
I really appreciate this explanation, but I think I'm missing something about how the reset pin (pin 4) works. Since it's connected to the base of a PNP transistor, doesn't that mean that when pin 4 is set to low it will allow the Vcc current into the flipflop and set Q to LOW. From how I'm understanding your explanation, you are considering this transistor to be NPN. Let me know if I'm misinterpreting though!
My EE professor, prof Rigby (back in 1985 ) and his friend entered a contest to create a timer circuit in the late 60s. My prof said his timer circuit was the best functionally but lost to his friend's timer design even though his friends timer design was not as good as his. Apparently the reason why his friends timer design won the contest because it did the function with minimal components. His friends design is known as the 555 timer 🙂. The moral of the story during class was that a better design circuit is not always the best solution.
I am so old I had forgotten when I was taught about this cct. Now I am not sure if I understood it then nor if I cannot understand it now. I am looking forward to seeing how the application of its properties is done.
Great explanation, thanks...except I am stuck on some point I obviously don't understand. sWhen the output is high (S is H) and Q bar then being low there is no power flowing to pin 3, so no power going to pin3 - even though one would think it would if there was power getting through the flipflop. When S is Low Q bar is high and although there is power flowing through the flipflop, does it not then (through its inverter) cut off the power to pin 3? So how/when does power get through to pin 3? Sorry for such a dumb (I think) question... Ahhh...I watched the next video and it became clear Thanks
What an amazing video explaining the workings of the 555 ... So well explained .. Gave me a far better understanding of it ,and how to use it , in all 3 forms ... Excellent video .. I also checked out the 2nd video you did as well .. Regards, - Anthony
nice explanation of the parts of the schematic and how the connect. Sadly that is all I got from it. Here's my problem though: A the start of the video I read that it is a "555 timer", so I assume it keeps time somehow. After watching, I understand that in fact it has functionality to compare voltages and weirdly contains an inverter when the Q pin could have been used to the same effect. The output of the compares goes into another thing. There are some pins too and I now know what they are connected to. An analogy would be if you showed me a washing machine in peices, but called it a motor car and explained that "this bit changes voltage levels" or "this bit spins" or "this bit pumps" then at the end said there are different modes. I'd have no idea what it did or how it worked.
Correct me if I am wrong, however there is a minor error: At minute 6:37 you state Q2 is off. A PNP is ON when the base is lower than the emitter. Additionally, the current limiting resistor should be placed between switch and Q2 base.
@@PankajYadav-hr8tp - Why? If you want a clock, a crystal-based oscillator is the way to go. You can cut bread with scissors, yes, but why not use a knife? Given the fact that ohmic resistance changes with temperature and even a 1% tolerance in capacity and resistance is a huge deal for a clock (problems a quartz does not have, by design) would make a 555-based clock pretty darn inaccurate. Sufficient for processor clocks or something I guess, but not for an actual clock.
@@mediocreman6323 well actually ,there is much more than the clock ,and it's a part of it...since the video was for education purpose, I guess the extra part will not be relevant.....and moreover the scissors are pretty much used than knife whenever you want to create something special than the usual work to do...
@mediocre man: ok, scissors are two knives with a hinge, but the 555 is not made of two quartz oscillators, so if someone wants to use the 555 as a clock, there‘s nothing wrong with that. It is not necessarily going to be accurate, but even to cut bread, cutting it with a paring knife, or a chef knife, or even a Swiss Army knife is not going to give you the same result as cutting it with a bread knife, although either one of them is a knife... 🤪 ✌️
The Makers Local 256 makerspace used a 555 timer to make a soldering learning kit to build a board that "rolls" a 6 sided die made of LEDs. Pretty neat!
Joshua Pritt I soldered a similar kit in the project episode that followed the overview of ICs. Though my kit used a phase locked loop IC and a binary ripple counter. Would be neat to see a similar circuit but with a 555 instead!
What she doesn't say is that discharge is also connected to threshold or trigger to cause timing. In her graphic it wouldn't do much but charge up a cap.
Nice explaination. I have 1 question. In the block diagram, transistor at pin 4 is appeared to be PNP type. To turn it "ON" isn't that mean BASE voltage need to be negative compare to EMITTER? In the video you said when ever pin 4 is grounded, the transistor is "OFF" which is contradict with what I understand about PNP transistor type.
@@zeeebrenn I was just going to say the same thing but you beat me to it by about 17 hours. Note to self: Wake up in the MORNING, not the EVENING. And, Happy new year.
Your observation is accurate. The IC indeed becomes active when pin 4 is high, and applying a low signal at pin 4 resets it. To rectify this, we can interchange the positions of the switch and resistor. Specifically, we can connect the switch between VCC and the base of the PNP transistor, while the resistor should be connected between ground and the transistor's base.
Am I right that if one measures the resistance between pin 8 (VCC) and pin 5 (control voltage) one should get 5 kOhm ? Or is it more complicated ? ( I am trying to troubleshoot some PSB, and my on board measurement between these pins gives 120 kOhm)
transistor to transistor logic to op amp to flip flop to logic gate to NAND gate to binary adder to microprocessors to CPU, we have come a long way in short a period of time, Human ingenuity!
Nice job and presentation! Can you give some kind of advise for something more complicated i.e. PS21245-E (intelligent power Module), how I could drive it & control it with a simpler circuit.
Wow. The number 5 in spoken Thai is “Ha”. So 555 is like lol, 555. I was looking for video to send for the 555/lol and am now subscribed to your channel 555.
Sorry, but just to be sure I have understood: At moment @6:26 when you explain the Reset pin, it seems looking at the video that the behaviour is the opposite: if Q2 is a PNP transistor, when base is connected to Vcc, it is OFF and set RESET of FlipFlop to LOW (resetting it), but from the video it seems that vhen the base is HIGH, the current is flowing from Vcc through Collector to Emitter and to RESET (tipical for a NPN transistor). The final effect is correct but I think the animation should be the opposite. Is it so ? Thanks
It was not directly mentioned that the power connections are not industry standard, having been designed before those standards were established. (VCC on 8 and VEE on 4) Nice presentation. Ron W4BIN
I've always wondered why the 555 seems to be like THE chip that everybody cuts their teeth on when they start electronics. For me, I remember it was rather confusing trying to learn about it as a newbie to electronics. But if the whole idea is to cut your teeth on using chips, why not start with a simple logic chip? I think an inverter would be a great chip to cut your teeth on. They're straight forward, and easy to use. AND you can make an oscillator out of them by chaining together an odd number of inverters. It might not be as versatile as a 555, but for a newbie who's just learning and getting comfortable with ICs, I think it'd be much better. Now you just need to do a complimentary video on how the 7555 differs from the 555 in terms of functionality on a transistor level.
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I’ve watched four different explanations on the NE555 internal workings and so far this one has made the most sense. A bit fast in places but it’s a video, I can go back and watch it again and try to pick up what I’ve missed. Thank you so much for your time and expertise on the subject matter and for “dumbing it down” in plain words and diagrams so that more people can enjoy electronics.
this is one of the best explanations of the inner workings of the 555 timer that I have seen in a long time!
This is one of the best presentations for working of the 555. We've used the 556 as astable and monostable together to produce a PWM signal for a Boost Converter, 12v t0 48v DC at St. Joseph's Research, BLR, IN.
Very nice tutorial, especially given it can be configured 3 major ways. I am a math guy that hobbies in electronics and studied the 555 a few months back. It was nice that your video mentioned that the integrated flip flop actually used only one of the outputs which is a detail that often is overlooked in other explanations. I ended up building an astable Multivibrator so that I could put out a weak signal in the AM broadcast band spectrum in order to test reception capacity on regenerative radio receivers that I assemble from parts at hand. It worked, barely. By barely I mean that high a frequency was kind of pushing my luck. Without filters it was also broadcasting everywhere much like a skipping stone across a pond.
How did u manage to do that how could you send out a wave using the 555 timer never mind I am a late bloomer my brain would take too much time to process but I would very much love an explanation
@@akashsunil7464 Its been a year or two, but as I remember I set the IC555 to the highest frequency that I could get it to oscillate at using the configuration shown on the data sheet. This was a matter of selecting as I remember resistors at specific pinouts.
The frequency that I was able to get was around 500KHz. I then added an audio transformer to the endeavor so as to inject audio such as a tone, into the signal it was generating thru being allowed to oscillate.
It was a lousy transmitter but it did put out enough mili-watts to be heard by a radio in the next room. It also had a square wave & produced harmonics all over the place.
Its kind of funny in that back then I spent a day or two understanding the entire innards of the chip & what could be done with it. I barely remember any of the details anymore. None the less its better suited for turning your car's dome light of than using as a low power transmitter
I have seen so many videos about 555 in my native language but somehow they were confusing until i found this video simple and understandable even with a foreign language description
Great channel! Your explanations are so clear
i used them a lot but never looked closely opn how they work, very informative, thx Karen!
I wish we’d had resources like this when I was studying Electronic Engineering and building 555 circuits back in 1981! Such a great little timer, I built all kinds of alarms and flashing lights etc with them, but getting across all of the concepts etc was much more of a dry subject than it is today. I really like how simple and clear you made this for people starting out. Great stuff.
I mean, that goes for any tech, right? I learned programming in the 80s, and you'd buy a single book on a single topic, for 80 bucks.
@@larrybud I'm 68. In the 70's they had mainframe computers behind glass doors in my college that ran tape. I thought writing instructions with zeros and ones was tedious. In 2008 I discovered I could control the behavior of motors by writing instructions. I was hooked and realized I had wasted my college career.
@@larrybud I still have some of those overpriced and dull books on the shelf lol.
There was very little choice of content at all and most of it was presented in a way that made things more difficult than they needed to be. I don't know about you but I had a mix of some very good lecturers and some that were just terrible.
Luckily I worked with some very helpful people while studying and was given projects that helped me learn and keep it interesting.
@@awaitingthetrumpetcall4529 In the early 80s I was initially more interested in electronics (and cars/motorcycles lol) than computing but got exposed to personal computers as well as the mainframes in the telco space.
In the early days most of the electronic projects that I built for myself were for cars and bikes - I built a full car computer that monitored fuel consumption and distance etc, car and bike alarms, electronic central locking.
I got into computing outside of work in a big way when the Amiga 1000 came out (prior to that had a z80 machine at home), but the Amiga was a game changer. It could be programmed to play music properly and could display quality photos - something that the IBM based business machines just couldn't do.
@@markedwards4879 I would have seen you as as an intelligent nerd. My only involvement with computers was playing "Pong".
A good 50 years ago I started in electronics making my first medium wave receiver with an ECC82 valve. A year or two later, in 1972 the 555 was introduced and I've been dabbling with it ever since. Thank you Hans Camenzind ! Nice video BTW 👍.
My understanding for electrical concepts is not enough yet, but I loved how every pin was explained in detail. Hopefully I can comeback to this video to understand it. Thank you for such a descriptive video.
First time I've seen an understandable description of this chip. Thank you. By the way, I have a friend who says he's bistable, but practicing as monostable because it's just easier to live that way. All good wishes!
A little bit fast in places, but a very useful video nevertheless. It certainly helps to demystify what's going on in the chip.
I'm by no means an expert in electronics yet the way you explained it was so good that even I understood everything.you deserve a sub
This has got to be the best video i have seen that explains how to use a 555 chip with proper illustrations of how it works
Wow, I wish I had a teacher like you, decades ago. It could've been career changing. Nice to learn the basics. Kids these days leap jump straight to a raspberry Pi and they find basics, pointless.
I've never seen a high quality explanation like that. Congrat!
Great video.
I’d also add that the rs latch is basically an electrical version of a mechanical toggle switch. But unlike the mechanical toggle switch the rs latch has 2 dedicated physical quantity inputs (either high or low) to change the state of the output.
The mechanical toggle switch has a single algebraic input consisting of the application of a + force or a - force to change states.
This 555 timer is an example of an application of the rs latch thru the use of the 2 comparators assigned to each of the 2 physical quantity rs latch dedicated inputs.
Such a configuration can be used for automatic temperature control as set with a thermostat .
And so that’s potentially an additional practical implication (besides an oscillator) of an rs latch configured with a couple of comparators to change states to turn furnace on or off to reject heat loss effects thru the walls of a heated building.
Unlike the oscillator both the period and duty cycle of the 555 output behavior in the furnace example will change depending on outside temperature.
The explanation that left me with no questions. THANK YOU
If I’m correct, Pin # 4 is the Base of a PNP transistor which Is set Hight turning the transistor OFF, and when the switch is pressed the base is grounded, an therefore the PNP transistor should go ON.
Thank you
gusel9 I agree. That is why the emitter is connected to Vcc internally as shown.
I'm so glad someone else caught this it was driving me crazy!
Arguably the most used timer ever.I started using this in the 70’s.(okay I just dated my self:-)Great explanation.!
Don’t feel bad, me too. One of my favorite ic’s.
Finally I get the hang of the circuit inside NE 555. Thank you!
Great job Karen! Wonderful job explaining. You are getting very good at quality examples and the discussion of complex items.
So excellent in explaining!!Coming upon a female electronics engineer made this more exciting to learn. Good for you, indeed! I thoroughly enjoyed this!!
I usually don't leave a comment for most of the videos but this one was Awesome explanation
Great explanation, Great visualizations, Great tutorial. Thank you very much for this.
Glad it was helpful!
Yup, that didn't even bump my head as it went over. Her well executed explanation still left me just as confused as whence I came. I just need a 3 second delay on a 12 volt circuit.
I allready use this when i made an inverter 12volt dc to 220 v ac since 1995, i was happy that it's clear explanation thank karen, thank yuo very much....
I loved your way of explaining...Very grateful!
You should consider checking out DC to Daylight too: ruclips.net/p/PLwO8CTSLTkiiBLUDE3vfOGjvIuQONT4AC
Great Graphics!!! Contrast and highlighting is properly used without unnecessary distractions. The “ how it works” part is fascillitated by Karen, who shows both Teaching Experience and Knowledge of the subject. As a Presenter, she is comparable to Liliana de Castro, who does Group Theory for Socratica. All pins were covered without the dismissive “ this pin is seldom used” . I hope to see Karen in more videos.
I had to watch this 5 times to wrap my head around it. Not your fault. Thank you.
"Thank GOD", and thank you, thank you very much for your presentation 😉 REALLY Really really good 😎
6:30 "If pin 4 is ever grounded, going low, the transistor is turned OFF."
Actually, it's the opposite because this is a PNP transistor, so it is held OFF while pin 4 is high, and it turns ON when pin 4, its base, goes low.
Well arranged presentation! Lots of good points for operation and I will watch the modes presentation next!
this is better than the videos that just show projects with the 555
LoL. And all through college we just slapped them in and looked up what C and R needed to be. Never dug inside them like this, thanks!
Nice vintage scope in the background.It seems to be a Tektronix...Great, detailed explanation of the 555...Thank you for posting.
Great work here showing how the basic building blocks become more complex circuits
Superb, Milady! I always have some..10 or 15 of them in mi parts bin. I had even made some NCG control boxes for cars and there They are, working almost 10 years later! I had a book (ugly, fat,big book) that I can't find nowadays, about the 555, and it stated somewhere; "555's are like rice....there are more than 1000 recipes wit them!". Thanks a lot for your videos! And "hi.5!" from Argentina!
556 can be used for many circuits.You probably know but others might not.2 555,s on a single chip was a good idea.
Super prezentacja, doskonale wytłumaczone. Dziękuję.
Do you see anyone else here speaking that?
Much better than my university electronics course!
Fantastic job done! Well defined and explained. She is great!
Fine explanation. Had watched many tutorials but this was the best. Thank you so much. A small point. In your next videos please try to make a little bit slow in words. As some of my friends felt so. Then persons who are not very conversant in English will enjoy it more
Very useful
We call it Triple 5 (timer), in my area in Australia
We also say 5k (for the resistor, five Kay),
We are already metric so we understand 1K etc
This is the first video I watched from you and I loved it. I used the 555 many times over decades but never understood it in such depth. Very useful and helps with troubleshooting circuit design.
One thing I may not be understanding is that when you said that when pin 4 is grounded, the transistor turns off. Being a PNP, shouldn't it come ON when the base is brought to ground?
Maybe i misunderstood?
Awesome tutorial I m new to electronics but well understood thanks Maa'm
Nice presentation, Karen and thank you for the information on the internal operation of the 555 engine.
omg finally a fully detailed tutorial for people who hav 0 knowledge
I really appreciate this explanation, but I think I'm missing something about how the reset pin (pin 4) works. Since it's connected to the base of a PNP transistor, doesn't that mean that when pin 4 is set to low it will allow the Vcc current into the flipflop and set Q to LOW. From how I'm understanding your explanation, you are considering this transistor to be NPN. Let me know if I'm misinterpreting though!
I agree. I think there may be an error in either the diagram or description.
My one and only breadboard slash 555 timer electronics project. Has a battery, a pot, an on off switch and a variable time on off LED. Cool.
My EE professor, prof Rigby (back in 1985 ) and his friend entered a contest to create a timer circuit in the late 60s. My prof said his timer circuit was the best functionally but lost to his friend's timer design even though his friends timer design was not as good as his. Apparently the reason why his friends timer design won the contest because it did the function with minimal components. His friends design is known as the 555 timer 🙂. The moral of the story during class was that a better design circuit is not always the best solution.
I am so old I had forgotten when I was taught about this cct. Now I am not sure if I understood it then nor if I cannot understand it now. I am looking forward to seeing how the application of its properties is done.
Thank You, this was a great intro video.I found Your explanation easy to follow and understand!
Great explanation, thanks...except I am stuck on some point I obviously don't understand. sWhen the output is high (S is H) and Q bar then being low there is no power flowing to pin 3, so no power going to pin3 - even though one would think it would if there was power getting through the flipflop. When S is Low Q bar is high and although there is power flowing through the flipflop, does it not then (through its inverter) cut off the power to pin 3? So how/when does power get through to pin 3? Sorry for such a dumb (I think) question...
Ahhh...I watched the next video and it became clear Thanks
Thank you so much for helping me figure this out!!!! It took me a long time to conceptualize how ICs work
Loved the presentation for the schematics.
Awesome thanks. Very well presented and I’m looking forward to learning more now!!
What an amazing video explaining the workings of the 555 ... So well explained .. Gave me a far better understanding of it ,and how to use it , in all 3 forms ... Excellent video .. I also checked out the 2nd video you did as well .. Regards, - Anthony
nice explanation of the parts of the schematic and how the connect. Sadly that is all I got from it. Here's my problem though: A the start of the video I read that it is a "555 timer", so I assume it keeps time somehow. After watching, I understand that in fact it has functionality to compare voltages and weirdly contains an inverter when the Q pin could have been used to the same effect. The output of the compares goes into another thing. There are some pins too and I now know what they are connected to. An analogy would be if you showed me a washing machine in peices, but called it a motor car and explained that "this bit changes voltage levels" or "this bit spins" or "this bit pumps" then at the end said there are different modes. I'd have no idea what it did or how it worked.
I would have to put this to practical use to get this into my memory Thank you!
This was such a helpful video, thank you!!
Correct me if I am wrong, however there is a minor error: At minute 6:37 you state Q2 is off. A PNP is ON when the base is lower than the emitter. Additionally, the current limiting resistor should be placed between switch and Q2 base.
Wonderful video but only at 6:33 you made a mistake. That pnp is connected to reset. Only Grounding it will turn on.
your explanation is perfect
Excellent presentation. A transcript of the script in the description wouldn't be too long and would be very useful. Regards.
Nice one ...super excited for the next episode ...now I can make my own clock...please explain by using a clock in the next video
If you want to make a clock, use a quartz oscillator.
@@mediocreman6323 thanks for the reply ..but I want an alternative option also...let's do something new
@@PankajYadav-hr8tp - Why? If you want a clock, a crystal-based oscillator is the way to go. You can cut bread with scissors, yes, but why not use a knife? Given the fact that ohmic resistance changes with temperature and even a 1% tolerance in capacity and resistance is a huge deal for a clock (problems a quartz does not have, by design) would make a 555-based clock pretty darn inaccurate. Sufficient for processor clocks or something I guess, but not for an actual clock.
@@mediocreman6323 well actually ,there is much more than the clock ,and it's a part of it...since the video was for education purpose, I guess the extra part will not be relevant.....and moreover the scissors are pretty much used than knife whenever you want to create something special than the usual work to do...
@mediocre man: ok, scissors are two knives with a hinge, but the 555 is not made of two quartz oscillators, so if someone wants to use the 555 as a clock, there‘s nothing wrong with that. It is not necessarily going to be accurate, but even to cut bread, cutting it with a paring knife, or a chef knife, or even a Swiss Army knife is not going to give you the same result as cutting it with a bread knife, although either one of them is a knife... 🤪 ✌️
Thanks ma'am i have never learnt ne555 ever like you told love you.
The Makers Local 256 makerspace used a 555 timer to make a soldering learning kit to build a board that "rolls" a 6 sided die made of LEDs. Pretty neat!
Joshua Pritt I soldered a similar kit in the project episode that followed the overview of ICs. Though my kit used a phase locked loop IC and a binary ripple counter. Would be neat to see a similar circuit but with a 555 instead!
Joshua Pritt That sounds quite interesting, you wouldn't happen to have a link to that, would you?
What she doesn't say is that discharge is also connected to threshold or trigger to cause timing. In her graphic it wouldn't do much but charge up a cap.
the best ... simple and clear, applause...
Incredible lecture! Just have a question. What is the triangle attached to the output pin? Look like it inverts the !Q output.
That's exactly what it is, an inverter.
Excellent explanation madam.Thank you very much
Nice explaination. I have 1 question. In the block diagram, transistor at pin 4 is appeared to be PNP type. To turn it "ON" isn't that mean BASE voltage need to be negative compare to EMITTER? In the video you said when ever pin 4 is grounded, the transistor is "OFF" which is contradict with what I understand about PNP transistor type.
Yes, you are right, the pnp explanation is wrong, when the reset pin is pulled high to VCC the transistor is off. But her schematic is correct.
@@zeeebrenn I was just going to say the same thing but you beat me to it by about 17 hours. Note to self: Wake up in the MORNING, not the EVENING. And, Happy new year.
@@zeeebrenn Yes, and I guess that is why in applications when the reset pin is not used, it is permanently connected to VCC.
Your observation is accurate. The IC indeed becomes active when pin 4 is high, and applying a low signal at pin 4 resets it. To rectify this, we can interchange the positions of the switch and resistor. Specifically, we can connect the switch between VCC and the base of the PNP transistor, while the resistor should be connected between ground and the transistor's base.
I like ur way to explanation in detail, thanks
Wow! great to find this channel. Superb explanation
Very good explanation of working
it is explained superbly! thanks and respect!
Thats the best internal diagram ive seen of a 555 yet
Very nicely explain the working of 555, love u thanks
Am I right that if one measures the resistance between pin 8 (VCC) and pin 5 (control voltage) one should get 5 kOhm ? Or is it more complicated ? ( I am trying to troubleshoot some PSB, and my on board measurement between these pins gives 120 kOhm)
transistor to transistor logic to op amp to flip flop to logic gate to NAND gate to binary adder to microprocessors to CPU, we have come a long way in short a period of time, Human ingenuity!
Nice job and presentation! Can you give some kind of advise for something more complicated i.e. PS21245-E (intelligent power Module), how I could drive it & control it with a simpler circuit.
Wow. The number 5 in spoken Thai is “Ha”. So 555 is like lol, 555. I was looking for video to send for the 555/lol and am now subscribed to your channel 555.
Wait,pin 4 consists of pnp transistor,as you said if pin 4 grounded its turning off?🤔
No it’s an npn but it is shown as a pnp in this drawing.
LOL I remember using this IC in electronics class in high school back in the 80s... It was the basis of so many TTL based circuits we made.
Sorry, but just to be sure I have understood:
At moment @6:26 when you explain the Reset pin, it seems looking at the video that the behaviour is the opposite: if Q2 is a PNP transistor, when base is connected to Vcc, it is OFF and set RESET of FlipFlop to LOW (resetting it),
but from the video it seems that vhen the base is HIGH, the current is flowing from Vcc through Collector to Emitter and to RESET (tipical for a NPN transistor). The final effect is correct but I think the animation should be the opposite. Is it so ? Thanks
Q2 is off when switch is off, and halfway on when switch is on.
Good explanation; FWIW I thought the narration was at the correct speed. Anyone complaining can always use the speed controls to slow it down :)
Thanks for the video. I learned and enjoyed.
As a visual learner, I'd have to see what happens during operation. I understand the 555 in a very broad way, though. Great video. Maybe a bit slower.
I think this series is a great idea 👍
Awesome stuff. I hope you cover how the 6502 cpu works one day.
Really good presentation
It was not directly mentioned that the power connections are not industry standard, having been designed before those standards were established. (VCC on 8 and VEE on 4) Nice presentation. Ron W4BIN
Thanks for explaining why this IC is called '555'
No not necessarily, may be the the designer was drunk and couldn't count further then 5 at that time, what you guess?
@@harrydelange1821 Or maybe the name was arbitrary, as the gentleman who designed it seems to think: en.wikipedia.org/wiki/555_timer_IC#Part_name
Excellent learning program 👍
Nice Video,... Ah an industry standard,... where would we be without the good old Signetics 555
I've always wondered why the 555 seems to be like THE chip that everybody cuts their teeth on when they start electronics. For me, I remember it was rather confusing trying to learn about it as a newbie to electronics. But if the whole idea is to cut your teeth on using chips, why not start with a simple logic chip? I think an inverter would be a great chip to cut your teeth on. They're straight forward, and easy to use. AND you can make an oscillator out of them by chaining together an odd number of inverters. It might not be as versatile as a 555, but for a newbie who's just learning and getting comfortable with ICs, I think it'd be much better.
Now you just need to do a complimentary video on how the 7555 differs from the 555 in terms of functionality on a transistor level.
Thanks for the explanation!
Would you please explain in brief about pin 5 of the ne555 timer ic.
Thanks for presentation
very excellent tutorial
Thnx a million for you're videos! I really appreciate them! Alot! 😎