when and why did Photon Couplers become "Opto isolators"?

Thread Starter

RETIREDTECHNOMAGE

Joined Jun 30, 2018
8
This is a trivia question that has bugged me for many years. NO ONE has been able to give a satisfactory answer. In the early 80's , all the catalogs ( Newark, Allied, Derf etc ) listed the 4n32, 4n40 etc as Photon Couplers....Very Star trekkish.! Then...sometime in the late 90s ?....I blinked and these wonderful devices suddenly were called "Opto isolators"...( how Boring ). All MY schematics will always show them the PROPER way!.. but the rest of the world marches to the tune of the Boring Name..... I would love to know when the change was made...By WHOSE authority ....and mostly WHY would the industry do this? Thank you , in advance!
 
Some time ago, there was a slight difference between optocouplers and optoisolators, but they both do more or less the same job. I believe that language changes over time and I think today that they have evolved to mean the same thing as the older product disappears. Both perform the same function of isolation and the newer ones are much better.
 

Papabravo

Joined Feb 24, 2006
12,389
This is a trivia question that has bugged me for many years. NO ONE has been able to give a satisfactory answer. In the early 80's , all the catalogs ( Newark, Allied, Derf etc ) listed the 4n32, 4n40 etc as Photon Couplers....Very Star trekkish.! Then...sometime in the late 90s ?....I blinked and these wonderful devices suddenly were called "Opto isolators"...( how Boring ). All MY schematics will always show them the PROPER way!.. but the rest of the world marches to the tune of the Boring Name..... I would love to know when the change was made...By WHOSE authority ....and mostly WHY would the industry do this? Thank you , in advance!
Funny -- I graduated in 1969 and spent 50 years in the industry and never heard them called Photon Couplers.
 

WBahn

Joined Mar 31, 2012
24,684
When I first learned of them in the late 80's they were "optocouplers" and "optoisolators".
 

BobTPH

Joined Jun 5, 2013
2,021
Never heard of a photon coupler in my 50 years of electronics. Are you sure you are talking about the same device?

Bob
 

crutschow

Joined Mar 14, 2008
23,307
I can understand the definition of an optocoupler as being technically a "photon-coupled isolator", but I don't remember ever seeing an actual commercial device identified as such.
 

dl324

Joined Mar 30, 2015
8,869
I'd never heard of photon being used instead of opto until now.

I have an HP Optoelectronics Application Manual published in 1977 (first edition) and it called them optoisolators:
An opto isolator consists of a photon emitting device whose flux is coupled through optically transparent insulation to some sort of photodetector.

Curiously, they had multiple spellings for optoisolator: opto-isolator, opto isolator, and optoisolator.

An interesting book if you can find it.
 

Thread Starter

RETIREDTECHNOMAGE

Joined Jun 30, 2018
8
This is a trivia question that has bugged me for many years. NO ONE has been able to give a satisfactory answer. In the early 80's , all the catalogs ( Newark, Allied, Derf etc ) listed the 4n32, 4n40 etc as Photon Couplers....Very Star trekkish.! Then...sometime in the late 90s ?....I blinked and these wonderful devices suddenly were called "Opto isolators"...( how Boring ). All MY schematics will always show them the PROPER way!.. but the rest of the world marches to the tune of the Boring Name..... I would love to know when the change was made...By WHOSE authority ....and mostly WHY would the industry do this? Thank you , in advance!
I will admit that my sense of time is probably wrong. I graduated from Tech school in 1967. My Patent Number 4,206,390 mentions PHOTON COUPLER. >> "While light-emitting diode 10 is shown as the "motor-controlling means" and as a part of a photon coupler 116, it will be understood by persons skilled in the art that other devices may be used instead, such as an electric lamp, a relay type read switch and the like. The motor-energizing circuitry is conventional, containing a photo-sensitive switch, a relay or the like which is activated in response to the "motor-controlling means" to close a motor controlling relay switch to apply power to the motor.
 

Thread Starter

RETIREDTECHNOMAGE

Joined Jun 30, 2018
8
I will admit that my sense of time is probably wrong. I graduated from Tech school in 1967. My Patent Number 4,206,390 mentions PHOTON COUPLER. >> "While light-emitting diode 10 is shown as the "motor-controlling means" and as a part of a photon coupler 116, it will be understood by persons skilled in the art that other devices may be used instead, such as an electric lamp, a relay type read switch and the like. The motor-energizing circuitry is conventional, containing a photo-sensitive switch, a relay or the like which is activated in response to the "motor-controlling means" to close a motor controlling relay switch to apply power to the motor.
Also in patent number 4217616 ( from 1980 )

5. The circuit of claim 1 wherein said coupling means in a photon coupler, said semiconductor switch is a triac, and having a master control switch connected to said second source for selectively connecting and disconnecting the latter to and from the remaining circuitry.
 
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