In 1980 I used a 555 timer to build a temp controller for an thermopile cooled IR detector. It was not PWM but simply a fixed pulse width frequency modulated waveform driving a buck switching circuit. OP-amp comparator built in, and elegantly simple circuit was what I recall.
What a useful and great part - I have used it for years and I expect it still gets designed in to circuits and systems every day. I suspect if you tried to initiate the 555 timer in many of todays bean-counter run technology companies you would not be able to get approval to move forward with it. The approval staff (of usually all non-technical people who have not been a customer or called on one for a living) would say - "for the business case to be approved I need to know the one customer that will buy millions" and if you said - " millions of people will design that into millions of applications" they would say "not enough data... denied!!!
The golden age of semiconductors.... before finance and operations ruled the earth engineers did we went to the moon-and the US and our companies were financially strong I miss those days! RIP Mr. Camenzind - I hope your tombstone says " I did not need a business case - I made one on my own"
Honestly I never knew WHO invented the 555 or PLL I just thought was a product of semiconductor Cos.
But when the new method of Controlling motor speed w/o losing torque known as "Pulse width modulation" PWM and the controllers were a box of 3 cards full of discrete components and analog circuits. Nobody was thinking of using the 555.
so, I thought that if running the 555 in Astable multivibrator mode and using a VR you in effect could change the duty cycle and thus the duty cycle of the square wave output. PWM!!
I used such a circuit along with a NPN power tab and VOILA!! worked Perfectly. All in circuit One inch square or less.
So, I can say I was one of the first, if not the first, to utilize the 555 for PWM in motor control
So, now that I know who made such versatile device; HAPPY TRAILS Buddy!! Thanks.
The 555 was my intro into designing with ICs. I learned electronics in the Navy circa 1960 and understood only vacuum tube technology until the mid 70's when I bought a book which I believe was call the "The 555 cookbook" and a Powerace bread board. It was an epiphany, no more huge transformers,rectifiers or capacitors for filament current or plate votage; gone were sockets with all kinds of nasty wiring. Just sweet clean 5 vdc, a symmetrical caterpillar of an IC that you just push into a matrix of holes,some jumper wires and the next thing you know you've got a circuit that can do something. 46 years later and I have to say that changed my life! Thanks, and RIP Hans Camenzind, you've done more for me than the sum of the rest of my education.
Chief of R&D
Wow...I remember when the 555 came out - I was 12 years old, learning electronics in my basement workshop. It definitely had an impact on me - I spent hours playing with it along with opamps and TTL devices. Recently I bought some for a small hobby project and had fun all over again. How many designs are still relevant and useful after 40 years? Not many...RIP Mr. Camenzind.
Hans was my second employer, and one I will always remember. He was a brilliant analog designer. He left his post as head of R&D at Signetics, and launched Interdesign with the purpose of bringing analog integration to a broad market of products that otherwise could never afford it. The 555 was Interdesign's first project - he sold it back to Signetics for a flat fee, with no royalty. Interdesign was very successful, though, and he did well. Hans' enthusiasm and energy was infectious. For a young engineer, he was a wonderful man to work for. May he rest in peace.
A Book For All Reasons Bernard Cole1 Comment Robert Oshana's recent book "Software Engineering for Embedded Systems (Newnes/Elsevier)," written and edited with Mark Kraeling, is a 'book for all reasons.' At almost 1,200 pages, it ...