"The phone is a remarkably complex, simple device, and very rarely ever needs repairs, once you fix them." - Dan/Panther
Started by escuta, July 28, 2017, 10:47:50 AM
Quote from: escuta on July 28, 2017, 10:47:50 AMFrom a suggestion on the Singing Wires list, I had a look at one of the lamps which had a voltage rating marked of 24V. Someone there thought that the lamp may be of American origin rather than European.
Quote from: unbeldi on July 28, 2017, 12:32:15 PMThe inscription on the lamp clearly identifies the manufacturer as Philips NV. ...Selection of the right kind of lamp for your board probably depends on the design of the supervisory circuits. If the lamp current is switched with a line relay, its resistance is perhaps less critical, as when the lamp is directly inline with the station....BTW, a switchboard is not a machine. I find that characterization rather distracting. It's all manual work to make this equipment work.A step-by-step switching system could be called a machine.
Quote from: Alex G. Bell on July 28, 2017, 01:05:09 PMAh! Could not make out the "NV" although I'm familiar with their full name.
QuoteFrom the rear photo, it does not seem that there are enough relays in the unit for there to be line relays, probably just cord circuit relays. Even much larger PBXs such as WE 551 and 555 did not use line relays except when added individually for specific off-premises extensions.
QuotePanel and Crossbar (XB) exchanges were also referred to as "machines", no stretch at all for Panel and not too much of a stretch for XB. In fact the Bell System originally used the term "machine switching" rather than "automatic" or "dial" to refer to what generally became known as dial service. Funny but with the evolution to ESS with stored program control and even digital ESS with no relays to speak of, the term "machine" continued to be used. Old habits die hard.
Quote from: unbeldi on July 28, 2017, 02:02:30 PMFrom the small Kellogg cordless boards I know that they equipped only the 20-station boards with line relays, not the smaller ones.
QuoteAgreed. One might however say, that this switchboard contains simple machines, which are devices, like the levers of keys, that transform energy in a very basic manner.Originally, machines transformed energy into mechanical energy, but it has been extended to electronic devices, such as computers even.
Quote from: Alex G. Bell on July 28, 2017, 02:13:00 PMThat always seemed to me like a stretch to the breaking point. As I see it, just because the disk drives are machines that does not make the whole thing a machine. It's principle function is computation which does not employ mechanical devices, which just provide storage. I'd make the same case for a manual swbd.
Quote from: unbeldi on July 28, 2017, 02:19:26 PMI have lingering objection to that inclusion myself, and I don't promote the term for computers myself, but have come to accept it.
Quote from: unbeldi on July 28, 2017, 02:02:30 PMOh, I just used the NV without reference to the actual inscription on the lamp. I am not sure what it is that follow the mark "PHILIPS" on that lamp.
Quote from: TelePlay on July 28, 2017, 02:38:25 PMSeems "IMP." is an abbreviation but what comes after that, the font does not match.
Quote from: escuta on July 28, 2017, 03:38:15 PMThanks Alex G. Bell and unbeldi. That Ericsson Brazil plaque unfortunately has the type and number fields left blank.
QuoteOn the lamp, from memory (I put the lamp back in the switchboard), the figures following "IMP." (imperial?) look like "AA" but with the crossbar of the first "A" missing.
QuoteTomorrow I'll have a chance to remove another bulb. If I can I'll attempt to retrieve a different lamp to see if the stamp is any clearer. Thanks for the tip on the Ericsson review. I did find a list of them on the following page, however the links appear not to open the PDFs on the Ericsson site:http://runeberg.org/ereview/Are you aware of an current online source of the reviews? I have some more photos, will post some in this post and some more in another.