Introduction to 555 Timers | Basic Circuits

555 timers are an incredibly popular IC that is useful for timers, switches, LED blinking, and more, using a simple analog circuit and no programming. In this introduction to 555 timers, we discuss the pinout and review the internal circuitry and logic, which both gives it its name and drives its behavior. We explain the different 555 timer configurations, such as the monostable, bistable, and astable configurations though we get into more depth on those particular circuits in later tutorials.

0:00 Introduction
0:41 What is a 555 timer?
2:38 Internal diagram of the 555 timer
4:04 The internal portions of the 555 timer
9:57 Why we care about the internals
10:57 Monostable, bistable, and astable configurations
13:15 Overview and summary
13:37 The toast will never pop up

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[manuelp]

What a great video, wow. I'm watching this at 4 am and I'm not even studying EE. I'm truly amazed that this explanation is so easy to understand.

[tedbastwock]

This is a very, very valuable lesson. Thank you eternally for sharing

[mth]

Excellent explanation. Looking forward to the next few tutorials.

[WRMD]

Good morning "toaster guy". I am happy to see you have a video on this subject. I really enjoy your videos! With toast and coffee of course.

[DasIllu]

Usually SR/RS latches have a priority by design. So SR would be set priority, RS would be reset priority. I don't know if any priority is codified for the 555 or if all manufacturers cook their own stew here. But it should be consistent at least within batches.
Maybe i dig around in my chip collection and whip up a bistable circuit. IIRC i should have at least chips by 3 different manufacturers.
I think it with worth exploring since the 555 is an easy to use flipflop for example in power on reset circuits, or as part of an interlock.

[DevidasBhobe]

Why do you need flip flop and inverter why not just take opamp output

[emersonmelfort]

So well explained that even me a third world Neadertal can understand.

[borisdorofeev]

Calling it a timer was a bit of a misnomer, but I can see why they chose it. Too many other things this circuit could have been named depending on how it was put together.