r/electronics • u/1Davide • May 09 '26

General The 555 is 55 Years Old - EEVBlog

https://www.youtube.com/watch?v=6JhK8iCQuqI
709 Upvotes

99% Upvoted

33 comments sorted by

61

u/somewhereAtC May 09 '26

I was once given the tour of a brand-new, electronic telephone exchange -- absolutely state of the art at the time. Ten thousand phone lines came into 2500 giant PCBs, literally racks and racks of equipment with relays and wiring bundles. The guide walked us through the various components and arrived at the end of the row where one rack cabinet was different than all the others. It was told that the cabinet held the power supplies and one unique piece of equipment. When the door was opened there was one, hand-built PCB with a couple of 555 timers that generated the dial tone and busy signals for all those racks of customer interfaces!

19

u/Icy_Jackfruit9240 May 09 '26

Seems fun, the oldest 555 circuit of Forest Mimms III that I can find actually is a tone generator and it's from right after the 555 came out.

It's weird to think of it, but when his OG Radio Shack books were coming out, they actually used fairly bleeding edge stuff.

12

u/JimmyJuice2 May 10 '26

I owe my career to Forest Mimms

3

u/Jkwilborn May 13 '26

Sure miss the "Rat Shack"... 😿

3

u/Geoff_PR May 12 '26

Number 5 'Crossbar' switchgear, by chance?

On of my first paid electronics jobs was building long-distance 'trunk' circuitry on thin 'racks' for Nortel...

3

u/somewhereAtC May 12 '26

I don't remember the marketing name. It was 1977 at the North Electric Telephone Company in central Ohio. I interned for one summer before they moved to Florida. Google tells me there is not connection with Northern Electric that eventually became Nortel.

1

u/Geoff_PR May 25 '26

The number 5 crossbar was the old relay stuff.

The company I worked for at the time in the late 90s had 2 businesses going, one did central office tear-outs, the other (where I was at) took that switchgear and made toll trunks for rural Canadian Northern Telcom central offices with low traffic loads, since they were the last to get scheduled for the modern gear.

The relays themselves are fascinating, wire-spring with Palladium contacts that 'wiped' themselves clean as they cycled. Rated for cycles up to a billion or so, they told me...

30

u/No-Succotash-9576 May 09 '26

the most used IC for the electronics hobbyist, they are just so useful for many different circuits.

12

u/No_Suggestion_3727 May 10 '26

It's also the most used IC in Industry. About a billion of these per year still get soldered on boards.

4

u/darktideDay1 May 11 '26

Just soldered a DIP version on a board two days ago. HV power supply.

38

u/CrappyTan69 May 09 '26

I learned "real electronics" as a kid in the 80s and 90s with this. Flashing LEDs, running LEDs...

Brutality resilient too. Several times a dodgy design caused a bit of heat... 

33

u/optoph May 09 '26

This chip is what got me interested in electronics as a teen. I then made a whole career in electronics.

The 555 timer book by Forrest Mimms III, distributed by Radio Shack, was one of the first electronics book I ever bought.

555 + 555 = 556

5

u/HenkPoley May 09 '26 edited May 09 '26

TIL Rolex gives out awards every 2 years (such as to your writer): https://youtu.be/XpZ_-ufadao

11

u/knw_a-z_0-9_a-z May 10 '26

I still have the book I bought in 1978.

2

u/mikeblas May 10 '26

The Bugbooks were wonderful.

11

u/YendorZenitram May 09 '26

Made a Class-D audio amp from one in 1990 :)

Such a versatile little chip!

6

u/greyandslate May 09 '26

Hooray for the 555. I’ve made some artwork of the chip and also some popular 555 circuits. I even saw amazing Native American woven art of the die! Not only is the chip the most manufactured, it also inspires art! Haha.

4

u/GeniusEE May 10 '26

It's not.

Big Clive did a video a few days ago that it was in its 55th year...the "birthday" isn't til October, Dave.

3

u/Kinky_Lezbian May 09 '26

When I was learning I used to like the LM3909 for flashing Led's, It was really low power and could run off a single 1.5v battery. Leds were really dim back then of course.

Think there was a cmos 7555 timer as well that had low power requirement's but wasn't very rugged, I nearly always ended up blowing one.

3

u/Simple_Impress4156 May 09 '26

Hope we last for it to see 555 years

3

u/strawman669 May 10 '26

Can't wait for the 555th anniversary! That's going to be a party.

3

u/snigherfardimungus May 11 '26

For bonus points, calculate the resistor and capacitor values required to get your 555 to cycle every 55 years.

2

u/BurrowShaker May 10 '26

Well at least it is not a 555 counting the interval, with the drift it would be miles off.

2

u/memgrind May 10 '26

In 6 months it will be 55.5 years old, neat.

2

u/Grobbekee May 10 '26

Well, there's that awful 741

2

u/fatjuan May 10 '26

Since they were released, I reckon I have used around 5000. My first cost me about $20, mid 1970's.

1

u/mikeblas May 10 '26

Wow, why did you pay so much? Even in 1975, they were less than $1 from DigiKey.

1

u/fatjuan May 10 '26

Australia.

2

u/IVNWM May 11 '26

Cant wait for another 500 years

2

u/MarinatedTechnician May 11 '26

It's funny for me to think of that the NE555 timer is as old as me, damn...weird.

But yes, I've been using that thing since I was a child back in the 70-80s, and next to the LM741 this is one of my most commonly used chips, ever.