Oh god I feel old. I remember being an excited schoolboy thinking how magic this was when it debuted.
For me that is blue leds.
Haha, for me it was "LEDs".
EEVblog: The 555 Timer is 55 years old [video]
81–90 of 97 posts
Re: EEVblog: The 555 Timer is 55 years old [video]
#82Earlier quoted context omitted.
Using a cpu running software to emulate a handful of gates is just the furthest thing from interesting. It's the inverse of elegant.
Until you go to lay out your circuit board. There's a reason microcontrollers are used for tasks like debouncing switches.
I said uninteresting and inelegant. No one disputes that brute force is functional.
Re: EEVblog: The 555 Timer is 55 years old [video]
#83Earlier quoted context omitted.
> Almost every practical problem today is better solved by something else. I'm curious about this claim. It's certainly easier to just wire up a modern microcontroller, but is there a better option that involves no software and is likely to still work the same today as it did 50 years ago?
Why is no software so important? If you design your board well enough, you can route the programming ports somewhere you can program it in-situ, possible with other components that also need programming. But in terms of cost, a simple microcontroller is usually cheaper than a 555 nowadays, often doesn't require external components, and so even if all you wanted was a single function like an edge-triggered pulse, or g…
"Why is no software so important?"
Because nothing is faster and more responsive than direct hardware logic.
"a simple microcontroller is usually cheaper than a 555 nowadays, often doesn't require external components,"
Often? Every UC I've ever used has required a whole slew of caps and resistors just to get the thing to take in operative firmware through a programming port. Even the simple light flashers for vehicles that I've made using a UC and accelerometer need at least two caps and two resistors to make a proper circuit that allows for flashing info to the controller.
"so even if all you wanted was a single function like an edge-triggered pulse, or generate a single frequency, it probably still makes sense to use a microcontroller from a board design perspective."
Frequency generation? Inductor, capacitor, input voltage. Zero UC required and guaranteed to be cheaper.
"As soon as you want anything slightly more complicated, odds are you can replace a ton of other circuitry on the board with that single chip and a small program."
And accomplish things at a glacial speed that a basic hardware-only solution would've solved. As an example - BOSS pedals have basically zero latency because it is all analog. All these newer Line 6 and POD and other digital FX pedal makers have horrible latency, some I've measured past 50ms (almost as bad as trying to live-monitor a Windows Audio device.) It has been this way for the over 30 years I've been playing guitar.
Most times, raw hardware with zero software is THE way to go. Anything else is just a performance loss.
Re: EEVblog: The 555 Timer is 55 years old [video]
#84Earlier quoted context omitted.
I don't think you could do it. Not with the original BJT variant anyway. :)
Hmm, why not? For the astable configuration, you could use a 100F capacitor with R1 = 10 Meg and R2 = 7.5 Meg, for a 55 year period. Base current for the Threshold NPN will come from the Trigger PNP (and hopefully temperature drift matches OK). Other than maybe the 100F capacitor might have some variation in capacitance and leakage current over the course of 55 years ;-) https://www.digikey.com/en/products/detail/tec…
at 1% initial precision of just eg. LM555 itself, you're looking at +-0.5 year just from the chip's contribution. If you ever find 100F 1% precision capacitor and 0% precision resistors, you may maybe hit +- 1 year if the other conditions are perfectly predictable, which they are not.
For your chosen capacitor, manufacturer doesn't even bother providing the tolerances. :) Good luck with that.
Re: EEVblog: The 555 Timer is 55 years old [video]
#855:55 video released on May 5th, as per description :) For something feeling like a fairly specific IC, I remember seeing many projects that use it throughout the years in wacky ways - and seeing it makes me happy to know that the sentiment for this little piece is shared.
I remember reading somewhere that it's the highest-selling IC of all time, which is a little surprising! I'd have guessed the winner would be an op-amp of some kind.
555s are such delightful little guys. I used a pair of them, plus an ebay telephone line driver, to make an old telephone ring: https://hardfault.life/p/telco-2
One timer runs at the ~20Hz ring frequency, and the other runs at ~0.2Hz on a 20% duty cycle. The slow one's output feeds the enable line of the fast one, so you get 1-second burts of ringing, then a few seconds of silence, then ringing... just like a normal phone.
I moved about 5 months ago and haven't had time to get back to this project. The goal is to build a little phone company in a box, so I can have all my old PCs talk to each other with their modems.
Re: EEVblog: The 555 Timer is 55 years old [video]
#86Earlier quoted context omitted.
Using a cpu running software to emulate a handful of gates is just the furthest thing from interesting. It's the inverse of elegant.
Until you go to lay out your circuit board. There's a reason microcontrollers are used for tasks like debouncing switches.
"There's a reason microcontrollers are used for tasks like debouncing switches."
Because people are too cheap (or fail that hard at basic analog electronic control) to get a proper single-pole single-throw switch with a pair of MOSFETs in a monostable mode, or use an S-R flip-flop latch to debounce, or even a very simple R-C filter circuit.
"Throw a microcontroller on it and call it a day" is the surest sign of someone not properly educated in electronic engineering.
Re: EEVblog: The 555 Timer is 55 years old [video]
#87The 555 timer is still the most popular chip that hobbyists add to their parts inventory (see rankings at https://partsbox.com/ecdb.html ). I find this both interesting and curious — I'd say it has mostly nostalgic value at this point. Almost every practical problem today is better solved by something else. And yet it persists, I guess mostly because of beginner tutorials and first LED blinky circuits. One nice thing…
> Almost every practical problem today is better solved by something else. I'm curious about this claim. It's certainly easier to just wire up a modern microcontroller, but is there a better option that involves no software and is likely to still work the same today as it did 50 years ago?
Yes. Look at the old national app notes for the lm339 family of comparators.
Re: EEVblog: The 555 Timer is 55 years old [video]
#88A couple of years ago I used a 555 in an attempt to fix a problem I had with my Xiegu G90 ham radio. When sending CW (morse code), the radio would sometimes not see a "dit" (the short tone in morse code). I could reproduce it by tapping the paddle too quickly. My theory is that the G90 doesn't use interrupts to detect paddle presses, but rather polls those lines, and sometimes misses when a pulse happens completely i…
That's pretty clever. I've never used the G90, but apparently newer firmware improves the CW performance. The CW mode seems like almost an afterthought with that company.
Re: EEVblog: The 555 Timer is 55 years old [video]
#89A couple of years ago I used a 555 in an attempt to fix a problem I had with my Xiegu G90 ham radio. When sending CW (morse code), the radio would sometimes not see a "dit" (the short tone in morse code). I could reproduce it by tapping the paddle too quickly. My theory is that the G90 doesn't use interrupts to detect paddle presses, but rather polls those lines, and sometimes misses when a pulse happens completely i…
That's pretty clever. I've never used the G90, but apparently newer firmware improves the CW performance. The CW mode seems like almost an afterthought with that company.
It's too bad. It's a good mode for low power.
Re: EEVblog: The 555 Timer is 55 years old [video]
#905:55 video released on May 5th, as per description :) For something feeling like a fairly specific IC, I remember seeing many projects that use it throughout the years in wacky ways - and seeing it makes me happy to know that the sentiment for this little piece is shared.
I remember reading somewhere that it's the highest-selling IC of all time, which is a little surprising! I'd have guessed the winner would be an op-amp of some kind. 555s are such delightful little guys. I used a pair of them, plus an ebay telephone line driver, to make an old telephone ring: https://hardfault.life/p/telco-2 One timer runs at the ~20Hz ring frequency, and the other runs at ~0.2Hz on a 20% duty cycle.…
Just a guess:
building an amplifier from transistors is sometimes simpler/cheaper than using an op amp. And some designs don’t need the benefit of op amps.
On the other hand, building a timing circuit from discrete components is less obvious. And the 555 does so much of what often needs doing.
Also, the design was not patented so they were commodity chips right away.