Watching a 1959 movie (On The Beach).  Is this a current source symbol? - Page 1
Forum section: electronics / beginners

author: JoeN
author_rank: Frequent Contributor
timestamp: August 27, 2015, 09:05:42 am
content: Or did it mean something else back then? And more importantly, is there a short timeline history out there somewhere when electronic devices and certain symbols came into use or went out of use. It would be interesting to read. I'd even spring for a book if it was good and comprehensive. Dave tie-in: Movie is set down under about half the film. For comedic effect it has several big name American actors playing Australians, poorly. Some exteriors seem authentic though.

author: krish2487
author_rank: Frequent Contributor
timestamp: August 27, 2015, 09:48:03 am
content: The two circles touching is a transformer symbol, not a current source.http://www.daenotes.com/electronics/basic-electronics/transformer

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: August 27, 2015, 10:06:29 am
content: I saw some old switchgear that looked similar to that last night, at Hobart Tafe.IIRC (it was a real quick tour) it was some some sort of variable speed motor control, that was in fact a motor driving a generator driving a motor.There was all sorts of old stuff there, I said in a few years you'll have a museum, he replied that they already had one.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 27, 2015, 11:12:33 am
content: Quote from: krish2487 on August 27, 2015, 09:48:03 amThis link says it is an "Architectural Symbol",---it isnotused as a transformer symbol in Electronics.The two circles were commonly used as a current source symbol for many years,( Older books on transistor theory are full of them)

author: Delta
author_rank: Super Contributor
timestamp: August 27, 2015, 11:50:45 am
content: They are transformers. The same symbol is still used on modern HMI displays controlling switchgear and such.

author: mij59
author_rank: Frequent Contributor
timestamp: August 27, 2015, 12:00:01 pm
content: Its a 3 phase transformer e.g. 10kV/400V 630kVA each transformer powers a powerrail in the top of the cabinet.Both transformers are paralleled with the switch to the right of the transformer symbol

author: Shock
author_rank: Super Contributor
timestamp: August 27, 2015, 12:04:27 pm
content: The labels say.. top isolated voltage transformer and btm isolated voltage transformer.

author: matseng
author_rank: Frequent Contributor
timestamp: August 27, 2015, 12:19:50 pm
content: Thanks for the tip - now downloading On The Beach, and Fail Safe 1964/2000 editions.

author: krish2487
author_rank: Frequent Contributor
timestamp: August 27, 2015, 01:09:00 pm
content: Correct,2 points.1. A current source usually has a arrow showing the direction of current flow.2. There is a difference betweenelectricalandelectronicssymbols. In the earlier days, a transformer was represented using overlapping circles in a line or a wiring diagram. Nowadays, it is rare but the old timers use it.A transformer is a electrical item, a current source electronics item.Again, it is pretty evident from the year of the movie - 1959. Thats what gives it away as a transformer.Quote from: vk6zgo onTodayat 09:12:33 PM