Where have you actually come across a 555 timer in the wild?

[fcb]

I once found one buried in the carpet. It left 8 little holes in my foot.

[ErikTheNorwegian]

A wild 555 cought by the cat, right before it was to eascape out the window... and into the wild!

[amyk]

Historic note: In the original PC, the timer chip had three separate timers - it generated a periodic interrupt at 18.2 Hz for DOS, drove the speaker with another timer, and also did a third thing I can't remember.

Third is actually the first (timer 0): interrupt for the DMA controller to perform another DRAM refresh.  Every couple of microseconds I think.

The 18.2Hz is used by the clock (at least when DOS is handling it, I think?).  You can hijack the interrupt and use the count for something else (say, an in-game timer to trigger another frame of activity), but don't be surprised if your system time is running slow afterwards.

This, by the way, is precisely why, if a motherboard had a 555, it's not used to generate PC tones: the timer has a pin toggle mode which does it directly.  Give or take a driver for the PC speaker (2" 8 ohm in the old fashioned models, usually some piss tiny piezo these days).

All this stuff was integrated first into a SuperIO chip (along with all the other system functions, and serial and parallel), then into the South Bridge when that become a thing.  If your motherboard has a BIOS, it has all of this stuff in it somewhere; UEFI models may not, I don't know.

Tim

If you saw a 555 on a mobo, chances are that it's some other 8-pin IC with that marking code and not the timer. Ever since the first PC, its main timer is an Intel 8254 or compatible. There have been other ones introduced later but the 8254 should still be there, integrated into the chipset. Even Apple's computers now have one, ever since they switched to being (almost) PC-compatible.

[kx5]

Took a lot of searching, but I just found one in the wild....

Maximius Cmosinellidae? 

[ignator]

I saw one used in a timer for spraying from an aerosol can for room freshening. I think it was Glade brand.

[lemmegraphdat]

Product detect simulator for diagnosing and repair of ridiculously expensive date code printer. Sends a 4v pulse to the printer to fire the print head. The Pointy Hair wired the connectors wrong and blew the chips. Took them home and repaired from parts in my junk box.

[dexters_lab]

spotted this today and remembered this thread   

NEC C1555 variant of the 555 in this 8" floppy disk drive dated 1984.

[bitslice]

NASA uses them for jet engine control

http://www.techbriefs.com/component/content/article/ntb/tech-briefs/physical-sciences/5398

actually I searched for that just as a joke, joke's on me...

[Synthetase]

Used to find them in old joysticks. The stick moves a linear pot, changing the pulse freq of the 555.

I've also seen them in electric fence controllers for pulse generation.

[German_EE]

The 'bonnggg' sound on Kone Elevators as the doors open and close is generated by a 555 on the control PCB.

[Gyro]

Fan speed controller in Instek bench PSUs.


P.S. I think it still gets 'typecast' as a timer, whereas a couple of voltage comparators with tweakable threshold resistor chain, a resetable flipflop and a strong push pull output stage in a single package is a gift for a cunning low cost designer.

[CJay]

They're used in some of the HP Storage array cache battery charge controllers.

[RobK_NL]

In the PSU of a Keithley 2001

[tautech]

Nobody's mentioned kitchen toasters. 

[Rolo]

In my Philips outdoor lamp with dusk sensor.

[Brumby]

Nobody's mentioned kitchen toasters. 

Yes they have...

In my 20 EUR cheapie toaster, used as timer for the bread ejector thingie. With the obligatory knob on the side to choose how burnt you'd like your bread.

I've used it and will continue using it myself for all kinds of things, but you can hardly call what I do "production".

[T3sl4co1l]

I once took apart a microwave that used a UJT (Uni-Junction Transistor).  I think I've got you beat on that

Tim

[Cubdriver]

They were used as watchdog timers in the microwave generators a company I used to work for made for a piece of semiconductor processing equipment.

-Pat

[Enigma-man]

I saw a 555 used in a super simple switchmode step-up converter to power Nixie tubes.  Nine volts in, 170V out.
Comes in kit form with PC board and parts.  After doing a search for "nixie tube power supply" it showed up
in one of the images.  I suppose one could buy it today if one were looking for such a thing.

http://www.ledsales.com.au
The attached image is not mine

[Stray Electron]

Hundreds of millions of NE555's are produced every year, but I don't seems to actually come across them very often in products I've torn down or had a peek in. I have a little drawer full of them somewhere, but i doubt all those chips are manufactured only to be destined for our collective parts bins ))

I'm very curious to see where you have actually encountered them in the wild, and the particular function they've been drafted to perform in actual commercial/industrial products. They're so versatile, there must be some interesting applications out there...

  Back in the late 70s I worked for a major US food processing company. We used packaging machines that were made by Triangle Packaging Machine Corp in Chicago.  All of the timing in them was done via 555s.  There were a couple of dozen in there. This machine took a roll of plastic film and formed the bags like you get frozen vegetables in. It formed rolls of plastic sheeting into the tubes, heat sealed the side seam, filled them from one of four hoppers, pulled them down and heat sealed the tops and cut them off of the roll and formed and heat sealed the bottom of the next bag. The entire process took about 3 seconds and every operation was timed by a 555 circuit and each timer triggered the succeeding ones.  It actually worked pretty well but if something went wrong everything that followed it went wrong and things could get "interesting" real fast!

   Some of the old HP gear used 555s to drive a switcher type power supply. IIRC I've seen them in some of the HP-IB disk drives and, I think, in one of the old HP desktop calculators.

[setq]

I've seen a 555, 311, BD13x based naive boost converter in what appears to have been a display driver for a VFD (it was skip dived).  Looked 1980s vintage so might have been cheaper than a dedicated IC at the time. The display was smashed but was quite large. I built a replica of it a few months ago replacing the BD transistor with an IRF510 as it looked interesting and it's possible to get a good 500mA at 30v out of the circuit with some tweaks without anything exploding. Didn't measure the efficiency however. Picture below - no schematic I didn't bother:



555 on left running at ~50khz. Voltage ref at top. LM311 comparator in middle. IRF510 top right with inductor. Voltage divider at bottom. If the voltage gets too high it turns the oscillator off - dumb as chips.

[MadTux]

HP 8662/8663A SMPS controller also has an NE555 in it.
Found it a bit weird, cheap NE555 in a 40 or 75k$ signal generator

[timb]

Used to find them in old joysticks. The stick moves a linear pot, changing the pulse freq of the 555.

I've also seen them in electric fence controllers for pulse generation.

Yeah, surprised this wasn't mentioned sooner. I think Woz pioneered this method with the Apple II joysticks. If I remember correctly, it was a 556 and the joystick was actually two potentiometers. The CPU would time the incoming pulses to determine position.

A very elegant solution!

[Enigma-man]

Here's my very recently constructed 555 based Nixie power supply to run some 1.5" Beckman 7 segment displays as may have been seen in
another thread.

[whitevamp]

just yesterday i had opened up a Jensen 3022 LX car stereo amp, im guessing circa late 80's - 90's.  and found this little gem in there. a ne555.
http://elektrotanya.com/jensen_xa_3022_lx_sch.pdf/download.html
https://docs.google.com/document/d/1sA30dH34P9BgDo_b-63wjXetkeeazWKl5QKfJTQ5ELg/edit