555 Timer Modes Explained - The Learning Circuit

[@phildodd9942]

A fantastic presentation ! Anyone who can talk for 10 minutes and pack in so much information flawlessly deserves every credit that is going ! The "animated schematics" are brilliant too ! Well done - THANK YOU !

[@jayantnigam5912]

3:06 - Bistable mode 5:19 - Monostable Mode 7:38 - Astable mode

[@tinkmarshino]

my brain is not functioning today so I will save this for another day.. sometimes it is hard to be old.. thank guys..

[@abhijithanilkumar4959]

Try meditation

[@tinkmarshino]

@@abhijithanilkumar4959 already tried medication..;-) Thanks for the advice.. but at my age I would just go back to sleep..

[@abhijithanilkumar4959]

@@tinkmarshino I meant meditation Sir not medication

[@remy-]

It’s a shit movie haha. Too many changes between her and the circuit and too fast. Difficult to follow, also for a younger guy ;)

[@marcuspetterson2954]

​@@remy- Just press pause every time she says something and writes it down. Make drawings try harder to understand. There is something to be said about shit effort too you know.

[@raulcrudele1]

Very nice presentation! When I was an Engieernig student (mid 70's), I discovered 555 and made lots of timers, for me and my friends. I used them to switch off the radio, after say one hour. I used typical monostable mode. Switching components, they could be programmed for diffenent turn-off periods. After many years, the 555 is still one of the most versatile and useful components in electronics. I had to measure and draw the block diagram, with a hard work. Your video is absolutely fantastic. Regards!

[@jimedgar6789]

Another excellent video Karen. I can never get enough of this IC. Most videos say, oh here it circuit for flashing an LED, have a good day. There was missing a little bit about how the resistor values in BISTABLE mode control both the charging rate and the discharging rate and can be calculated to determine the duty cycle. Otherwise, spot on!

[@JohnClulow]

I find it very helpful to frequently hit "pause" so I can let what you've said soak in, and as others have said, the combination of well scripted, logically sequenced commentary along with the animated color graphics make this very easy to assimilate. I'm just getting into active components and find your videos so helpful! Not at all what I expected after all the Karen cat videos on Facebook.

[@jerryocrow1]

I hit it 124 times.

[@michaelboyce3227]

I also pause a lot, as well as tap the screen like a mad man to jumpback (which is seriously one of those features that's *_way_** underappreciated,* until using a videoplayer without it!) In addition, I recommend adjusting the playback speed to .75 for edu-vids, that are arranged well, present their content at an average ···⟩ above-average+ cadence, as well as information dense. (literally all other content goes the opposite way for me, all these YTers trying to hit their 'monetization mark' and stretch their videos either by speaking unnecessarily slow or adding 'fluff' so they get 1.25 ···⟩ 1.5 ···⟩ + playback speed)

[@pedrotorchio]

This is probably the best video on the topic. Thank you!

[@DarkModulator]

This very amazing video how to learn the 555, I wish I could had this when I was an electronic engineer. Learning with the hard way is rewarding but not fast. This video is the best

[@PurityVendetta]

Thanks, a clear and concise explanation of the 555 timer. Just what I was looking for.

[@mattbriancapangpangan9489]

I longed for this kind of tutorial when I was still in my vocational course. Appreciated to see this video now and was able to refresh this topic. Thank you for making such a wonderful tutorial. I am making a stepper motor control using JK flip flops and using this 555 timer as well to provide pulsating signal that will provide triggering step for the stepper motor.

[@kbi4739]

your clarity and presentation are the best i've seen so far. Thank you thank you thankyou

[@tamirtsuriel7718]

Really good and simply put. You should be professional teacher .

[@tze-ven]

With animation, it makes explanation very clear and digestible. I really like it. But, there are two mistakes there. At 4:27, (1) the PNP transistor should be OFF when the button is released, and ON when otherwise. (2) There should be a resistor at the emitter of PNP transistor associated to the RESET pin to limit the current, otherwise it would blow when the button is pressed. Actually in the original circuit of the 555 by Signetics, the transistor is not connected that way. Instead, the emitter of the transistor is connected to the reset terminal of the SR flip-flop (built using 2 NPN transistors and a feedback resistor) and its collector is connected to GND. The emitter resistor has a value of ~82kΩ.

[@sadunnakipoglu9471]

أشكرك وأقدر مجهودك ، تحياتي لك من تركيا.

[@xedover]

Very well done presentation, and easy to understand. In Ben Eater's series of videos to build an 8-bit breadboard computer, his clock module uses three 555 timers, one in each mode, astable, monostable and bistable.

[@bermchasin]

great series

[@5coffeebreak2]

Perfect discussion, many thanks for the valuable information with simple explanation

[@shaikaftabahmed9666]

just awesome , please keep bringing these stuffs it helps me a lot in my exams

[@lorpis8284]

Your videos on the subject made my project easy. thanks!

[@ianharvey868]

Use to create squarewave tone generator for projects. Also use in combination with the CD 4017 for better accuracy of timed sequence when used for longer periods of time, also multiple on/off in different timed themes, Really good for logic input due to no switch debounce

[@RhoTrepaan]

aha! now I get it. you're the first to get me to understand it ;'-) (I've watched both clips Thanks!) The schematics were very helpful o/

[@habtamusium8646]

glad to attend this class . thanks !

[@k_EC_ANURAGPAL]

u r awesome.....huge respect from india

[@Jonathan-ru9zl]

Excellent explanation!! I wish someone at the academy could explain it that way, back then, 15 years ago Interesting question: if we have this oscillating device, why we need quartz oscillator at all?

[@alpohree]

I love this explanation, so easy to follow. Thank you for this.

[@yashvratsingh5761]

Loved the prsentation and so much information in such a less time!!

[@mzand95]

A very clear explanations , thanks

[@JBM_95]

Great explaining video of the 555 ! Thanks very much !

[@kuime1]

This video is sooooooo good compared to the others with same topic! I wish I could give multiple thumb-ups 👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻👍🏻

[@sebastianthomas8507]

I learn how to use 555 from this video thank you

[@jfgobin]

Nice and detailed explanations on the venerable 555, thank you!

[@danielkerbacher3749]

Great explanation and wonderful graphics! Thank you for your super presentation!

[@dafnegarcia1596]

You are amazing, girlie ♥️ Thanks!

[@kabandajamir9844]

The world's best Queen teacher

[@gyrgrls]

The 555 was produced by Signetics in 1972. It was a marvel for its time, but many of the same functions can be done with two or three transistors and careful design. The heart of the 555 is a window comparator. Yes, it is an ingenious design.

[@dmitripogosian5084]

This and and the other presentation in the series are absolutely fantastic. Thanks !. One thing which was slightly unclear to me in bistable mode starting with low threshold, is why do I need to put trigger high to get high output, if it is high when trigger is low as well (with threshold low). So it seems there is no function for trigger to switch output high (it is high by default). Yes, then, to put output to low, you need to first put trigger low and then threshold high to avoid invalid state. But not to start ? It seems you just need to keep trigger high all the time and play with threshold ? My use case is when 555 is used as a standby switch to amplifier IC (TDA1554Q). 555 output is directly wired to 'standby' pin of TDA1554Q, which needs it to be around VCC for TDA1554Q to be on.

[@claytonbenignus4688]

I would also like to see presentations on the LM386 and the CD4040 similar to this one. Good Job!

[@LittleRainGames]

Op amp or comparator?

[@rahs2010]

Thanks for making it so clear.🙏

[@jagrutbhatt3301]

Very good information.

[@adamxu]

At 4:36, you said when the button is pressed, the transistor is turned OFF. I think you said it wrongly as the transistor is turned ON and the transistor's collector is pulled to Vcc which will fully reset the SR flip flop.

[@My-iTech]

@@adamxu you're right. The internal transistor is PNP it works only when the base is grounded

[@davidsmith1926]

Is it safe to short the base of a PNP transistor to ground as is shown at 4:35? Seems like it would need a resistor between the base and ground in order to prevent damaging the transistor because it would have to drop all of Vcc between the emitter and ground.

[@germ1saba]

Very interesting, you are good ❤

[@stew9456]

Hi, There appears to be an mix up in the video?? the image at 2:52 doesn't seem to correlate with the image at 8:51. The outputs are different when the transistor is triggered.

[@davidsmith1926]

Am I right that a 555 timer technically contains an SR latch, not an SR flip-flop? A flip-flop is edge-triggered meaning the inputs take effect only when a clock input goes low->high or high->low. A latch is level-triggered so the output changes whenever the inputs change level and doesn't need a clock. Since the 555 timer doesn't take a clock signal, I think it contains an SR latch not an SR flip-flop.

[@blackartista]

Best video on 555 timer explanation but a little mistake on pnp reset transistor over there as pnp enter saturation region (turns ON) when pulled low and cut-off region (turns OFF) when pulled high ✍🏾

[@michaelbenard6758]

Would you please explain in brief about pin 5 of the ne555 timer ic.

[@lmwlmw4468]

Great video.

[@sanjeevkumargupta6551]

Very nice explaination . Very very Thanks.

[@sathyamurthyponniah124]

@Sanjeev Kumar Gupta - Karen is reading the script at an express train speed that we cannot follow what she is trying to educate us about. If she tries to teach us something she must slow down

[@xavy_921]

Thanks ...happy new yr too

[@jamesturner2126]

Great presentation, great graphics, great info. I liked and subscribed

[@tusharpotdar5762]

Explained so beautiful, thanks, Soooooo. Good

[@chkuo9491]

hello i have a question at video at 06:35 when the capacity charging the switch should be open or close? i think the trigger pin be actived at a small period of time so when the capacity is charging the switch can open right

[@jamesturner2126]

Configured as an oscillator, will grounding pin 6 control the duty cycle of the TLC555? Maybe with a transistor and a feedback signal?

[@ZvikomboreroGandidzanwa]

Thank you. Thank you so much

[@turbinegraphics16]

I'm using the astable circuit for a turbo controller using a 10 microfarad capacitor with 66K and 680K resistors.

[@obinnankemdilim6682]

Hello Karen, In this demonstration, how do you calculate the value of the resistor connected between the discharge pin and the VCC?

[@hadibq]

I understand all what's said because I know how a 555 works, not sure if I can put myself in a noob's shoes 🤔 genuinely curioushow clear is the explanation to noobs with the prerequisites of voltage divider and rc circuit. again for most who know, I guess it's greately explained!

[@rrace2]

For astable or alternating, when the bottom comparator has between 1/3 and 2/3 vcc on the negative pin, then the output should be low, so no set on the flip flop and Qnot should be high then no? Or Qnot is low if set and reset are low?

[@dinosaur0073]

Little bit confuse. PNP of pin4. Positive from abundant supply and Positive from capacitor will capacitor discharge ?🤔

[@gonzaloroca4126]

Pretty good info. I like the schematics, I been trying some projects of my own, I think I've have to know more about flip flaps, is been a long time since I learned it. I really like what you and your team do.

[@grindel80]

Very good! keep on going

[@kckc9245]

Hi. I have a question how can i use the LM555 too get a square Wave on the output with a music sound input and adjustable speed. Thank you 👍

[@mu8502]

hey my friend I need to make a square signal that have not any small changes in frequency or pulse width but ics like 555 timer can not be like that and have small changes is there any way???

[@Alex_and_Gabes_Bad_Ideas]

This helps so much thank you.

[@rangaswamy8604]

Great explanation.

[@DrGod-rn5oj]

Please which pin can be used for output of 555ic than pin 3?

[@chaitanyadeshpande8362]

Mam please make video on astable multivibrator working and. Also on phase lock loops

[@michaelbenard6758]

Could you explain the IR2110 ic

[@ingussilins6330]

Put 6K resistors and make 666 timer :D

[@rationalthinker9612]

I have a question (monostable mode), initially in the circuit we push the moveable button closed so that it connects Pin-2 to ground, this makes C2 output HIGH which makes S = HIGH which makes the FF output (not-Q) go LOW, this LOW feeds into the transistor making it OFF which breaks the pathway between the capacitor and the GND associated with Q1 so that lets the capacitor charge. I am all good on that...then the capacitor gets above 2/3 Vcc and this makes C1= HIGH which makes the output of the FF(not-Q) go HIGH which then feeds into the transistor and turns in ON so it's ground can now connect to the capacitor to drain it. I am pretty sure that's correct, however what I don't get is the moveable button during the RESET stage, does the button stay pushed down and connected to GND, or does the button automatically move back up breaking from GND? How does the button move back into it's up position? I hope that question makes sense.

[@chrisr1382]

The pushbutton switch is a momentary switch. When you release the button, the switch opens up breaking the connection from GND (it's spring loaded) and moves back up to its original position.

[@rationalthinker9612]

@@chrisr1382 thanks!!

[@gerrys6265]

Ok, thanks...but I have yet to figure out how, when Set is High and output therefore is high...where is the full-voltage output coming from to power whatever it is that you want powered? What am I missing here? Cheers

[@savalakanekar95574]

Does this type of micro processor used in PESA radars?

[@murrrr8288]

great video thanks!

[@walkingrobin9965]

Still see d104 ....great video btw

[@Abdelhamid_Helal]

Great explanation

[@RixtronixLAB]

Nice info, thanks :)

[@SLB_Labs]

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!

[@Jasmine-mm7kl]

Thank you

[@aleaatz]

Very Good ! Thanks

[@DAVIDGREGORYKERR]

can also be used a a PWM modulator.

[@johnfist6220]

Why does pressing the button stop current flowing into pin 2. Wouldn't it just make it flow to both ground AND pin 2?

[@agustiandumeztina3721]

Hi,,i have project making vape by using ar ne555.. But i dont have enough watt for firing, then the capasitor change 103 to 104 but still same.. Wonder if i bypass pin5 to pin1 by one capasitor,, is it can or not ?

[@myokhinoo2726]

hi 555 ic voltage deviate how it work and other ic frequency output how it work please

[@Avionics2]

Thank you very much!

[@abdiaspablo7130]

Thanks for the reading

[@Dc_tech386]

Hi am trying to use a 555 to make and inverter for low side and high side but I can’t get it to inverter two signal and when I use a bjt to inverter the signal I get the same high side signal turning on the mosfet at the same time , I see a lot of circuit showing a bjt and it inverter the signal to two high and low but i the same circuit and all design end up with the same results the two mosfet turn on the same time

[@ابواحمدلكهرباءالسيارات]

قناة محترمه

[@jerryocrow1]

The five things that frustrate me as a student are (1) OOTB which is some fact, theory, or occurrence that happens "Out Of The Blue", that is, without explanation, reason, or causation, leaving the student wondering where that came from, (2) KOIK which is some fact, theory, or occurrence that is "Known Only If Known", such as giving directions to McDonalds as being "3 miles down the other road past where Smith's barn used to be before it burned down 20 years ago", leaving the student behind wondering why they don't know about Smith's barn and why there are no signs to it anyway if they were supposed to know about it, (3) DOGMA which is, some fact, theory, or occurrence that is stated as true without any foundation, proof, or agreement and which is not debatable, leaving the student to either ignore, reject, or wonder what was said, (4) MO which is some fact. theory, or occurrence that is stated and then, without time or warning, the lecturer "Moves On" changing the topic, image, and pace before the fact, theory, or occurrence "sets in", which leaves the student alone and behind, and (5) FINDING WALDO which is some reference to a visual without any cue as to where to look, requiring the student to stop thinking and scan scan scan until Waldo is found, which by that time, the lecturer has MOed, leaving the student behind in the dust. Any lecture should, like proof reading and grammar checking, should include (1) OOTB, (2) KOIK, (3) DOGMA, (4) MO, and (5) FINDING WALDO, checking for the same reason: To get the student's mental light bulb to turn on. Thank you.

[@jamese8595]

Can someone please explain why at around 8:40 the capacitor can change the input at pin 2?

[@QuincyN]

My understanding is that the capacitor stores the energy as it's charging and whatever voltage it's charged to affects the comparators because both of them are connected to the capacitor. As time goes on the voltage drop across the red resistors decreases because the capacitor is taking the role of using more voltage, so the voltages that the comparators are reading at their inputs increases as the capacitor charges. I think it would be safe to view the capacitors effect on the voltage at that branch before it as if the capacitor were a resistor that increases its resistance value over time. In both cases the voltage at that branch increases.

[@automaticman2010]

I'm pretty sure she meant to say pin 6 there, not pin 2. As the cap charges the voltage on 2 and 6 rise and when they reach 2/3 Vcc pin 6, not 2, sets comparator 1, which resets the flip-flop, causing the output to go low, which then begins to drain the cap and restarts the whole proces.

[@QuincyN]

@@automaticman2010 yeah, she mixed up the pins at that point.

[@farabielec]

Thank you.

[@GMLFree]

I have a question. I have Sega's master system and a Sega genesis AC adapter. The difference in voltage is only 1 volt. The master sys is 9 volt and gensis is 10 volt. If I use 10v for a 9volt machine ; is 1 volt difference enought to damage the machine's components?

[@rakeshkchauhan]

At reset level, the output immediately goes from 11V to 7V but stays there and reduces very slowly.

[@stewartrogerson1369]

I believe your Q2 logic is incorrect, the circuit is correctly drawn, Q2 would turn on with a low voltage (Gnd) on base and turn off with a high voltage (Vcc). looking at the bigger circuit, the positive voltage supplied from Q2 collector is the reset to the RS flip flop.

[@akkafietje137]

I use the 555 as a timer, but by applying the VCC, the timer starts already, while pin 2 is still connected with 10 Kohm to vcc and the switch to ground is not activated. What can be wrong ??

[@Nysmon]

Can I make bistable mode with one switch

[@hackfreehvac]

I used to use these things a lot before I got into microcontrollers.

[@BariumCobaltNitrog3n]

I used this to make a PWM for some leds (dimmer) Most or all PWMs connect pins 2 and 6 together to ground with a capacitor I used 100 nanoF. Pins 4 and 8 are connected to power (5-30vdc) 1 is ground 5 goes to ground with a cap, I used a .01 uF (all caps are ceramic, little flat brown ones) 6 also connects to power through a variable resistor, I used 50K, on the wiper and two diodes (1N4007 or equiv) connected to the other two pins on the pot, one facing each way (one toward and one away from the VR) then the two diodes connect through a resistor to power. I used 100 ohm Pin 3 goes to a resistor, I used 10 ohm, then the led (or strip) then to ground parts: 3 caps, 2 resistors and a variable resistor, 555 timer, power source, led Notes: This got me a 91% duty cycle, frequency of 1.2 MHz, period of 831 nanoseconds, on time of 762, off time 69 nanoseconds full bright and it dimmed down to 5%. Play around with the values of the cap (between pin 6 and ground) and resistors to change the frequency and on/off times depending on your voltage and light source. There is a 555 calculator online to find frequency and on/off times. Several actually. Good lux!

[@chakreshjoshi4302]

thanks

[@savalakanekar95574]

What is price of 555 processor with pin holder sockets?

[@dmitripogosian5084]

Not sure about sockets, chip itself is between 1 and 5 USD depending on variations

[@fieldsofomagh]

Needs to show visual output as buttons are pressed.

[@ASD82able]

Thanks