Somewhere over the past 60 years, ... possibly in between the Vodka's, Gin, Wine, Beer and wacky weed I seem to have missed the 'Symbol Change Memo' of what we used to call "Chassis Ground". The term "Chassis Ground" also morphed a bit with the advent of the PCB. This naturally gave birth to the term "Circuit Ground" because the metal chassis has become all but extinct.
Less I digress this post is about what used to be the standard electrical symbol for Earth Ground vs Circuit, Chassis, System, Signal or whatever Ground that is not actually Earth Ground. The Google image below indicates the accepted symbol for Earth Ground today but it used to be what's shown as "Chassis Ground"!
Personally, what's NOW shown as "Chassis Ground" makes a hell of a lot more sense as it used to be... "Earth Ground", because it more aptly visualizes earthed ground rods. It's also the way I was taught and later taught my own students.
Just to confirm that I wasn't loosing my mind I dug out some schematics of my 1930's and 1940's vintage test equipment and radio stuff. Some included Mil Spec equipment which were sticklers for preciseness. They confirm that my mind is still present and safely nestled between my ears. It also seems to still be firing on all cylinders.
So, who the hell changed it? When did it change? Why did they change it?
Chris
Less I digress this post is about what used to be the standard electrical symbol for Earth Ground vs Circuit, Chassis, System, Signal or whatever Ground that is not actually Earth Ground. The Google image below indicates the accepted symbol for Earth Ground today but it used to be what's shown as "Chassis Ground"!
Personally, what's NOW shown as "Chassis Ground" makes a hell of a lot more sense as it used to be... "Earth Ground", because it more aptly visualizes earthed ground rods. It's also the way I was taught and later taught my own students.
Just to confirm that I wasn't loosing my mind I dug out some schematics of my 1930's and 1940's vintage test equipment and radio stuff. Some included Mil Spec equipment which were sticklers for preciseness. They confirm that my mind is still present and safely nestled between my ears. It also seems to still be firing on all cylinders.
So, who the hell changed it? When did it change? Why did they change it?
Chris