Radio_Azureus555 timer Integrated Circuit
This gem is now 55 years old! A wonderful history is described in this vid.
Naturally I also looked in the wikipedia and Encyclopedia Britannica to find goodies of the time this wonderful timer was build. Since no patent was filed you can find a billion versions of it, which is a nice variant on the patent theme
Wikipedia states
The timer IC was designed in 1971 by Hans Camenzind under contract to Signetics.[3] In 1968, he was hired by Signetics to develop a phase-locked loop (PLL) IC. He designed an oscillator for PLLs such that the frequency did not depend on the power supply voltage or temperature. Signetics subsequently laid off half of its employees due to the 1970 recession, and development on the PLL was thus frozen.[6] Camenzind proposed the development of a universal circuit based on the oscillator for PLLs and asked that he develop it alone, borrowing equipment from Signetics instead of having his pay cut in half. Camenzind's idea was originally rejected, since other engineers argued the product could be built from existing parts sold by the company
We are sure glad marketing was on good insticts then
The first design for the 555 was reviewed in the summer of 1971.[8] After this design was tested and found to be without errors, Camenzind got the idea of using a direct resistance instead of a constant current source, finding that it worked satisfactorily.[8] The design change decreased the required 9 external pins to 8, so the IC could be fit in an 8-pin package instead of a 14-pin package.[8] This revised version passed a second design review, and the prototypes were completed in October 1971 as the NE555V (plastic DIP) and SE555T (metal TO-5).[9] The 9-pin version had already been released by another company founded by an engineer who had attended the first review and had retired from Signetics; that firm withdrew its version soon after the 555 was released. The 555 timer was manufactured by 12 companies in 1972, and it became a best-selling product.[6]
Quite neat this was for us electronic tinkerers and engineers
The 555 found many applications beyond timers. Camenzind noted in 1997 that "nine out of 10 of its applications were in areas and ways I had never contemplated. For months I was inundated by phone calls from engineers who had new ideas for using the device."[8]
sources
https://en.wikipedia.org/wiki/555_timer_IC
https://www.youtube.com/watch?v=6JhK8iCQuqI
#electronics #timer #timer555 #555timer #IC #engineering #mathematics #physics #no #TV
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