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What era did power supplies become switching?

PostPosted: Sun Mar 13, 2016 1:15 am
by shild
For desktop computers. About what era did power supplies become switching? Was it sometime in the early 80's?

Re: What era did power supplies become switching?

PostPosted: Sun Mar 13, 2016 3:19 pm
by tezza
That's a good question, but one I don't know the answer to myself. I imagine some Googling research will supply the answer but yea, I imagine the change happened around the late 70's/early 80s.

Re: What era did power supplies become switching?

PostPosted: Mon Mar 14, 2016 1:33 am
by shild
tezza wrote:That's a good question, but one I don't know the answer to myself. I imagine some Googling research will supply the answer but yea, I imagine the change happened around the late 70's/early 80s.


Me too. I was watching some of your video's trying to learn about that. Looks like your 5150 is switching. Interesting how the power supply looks like it has 2 fans? How about that Kaypro? Is that a switching supply?

Re: What era did power supplies become switching?

PostPosted: Mon Mar 14, 2016 9:59 pm
by TRS80
shild wrote:How about that Kaypro? Is that a switching supply?


My Kaypro 4/83 and Philip Avery's Kaypro 2 both use switching supplies. The TRS-80's from the Model III (1980) onwards use switching supplies. The TRS-80 Model 1 (1977) does not, nor is the Dick Smith System 80. The Apple II (1977) does and I heard on a recent podcast (Drop III inches from memory) that the Apple II was a very early adopter of a switching supply and they had some challenges getting it UL approved because at the time the standards people were not familiar with switching supplies.

Re: What era did power supplies become switching?

PostPosted: Mon Mar 14, 2016 11:33 pm
by shild
TRS80 wrote:
shild wrote:How about that Kaypro? Is that a switching supply?


My Kaypro 4/83 and Philip Avery's Kaypro 2 both use switching supplies. The TRS-80's from the Model III (1980) onwards use switching supplies. The TRS-80 Model 1 (1977) does not, nor is the Dick Smith System 80. The Apple II (1977) does and I heard on a recent podcast (Drop III inches from memory) that the Apple II was a very early adopter of a switching supply and they had some challenges getting it UL approved because at the time the standards people were not familiar with switching supplies.


Oh alright. Sounds like this all happened a little earlier than I thought... So do you have both kinds of TRS-80's?

Re: What era did power supplies become switching?

PostPosted: Thu Mar 31, 2016 10:45 pm
by TRS80
So do you have both kinds of TRS-80's


Sorry I missed your message. I don't have all the TRS-80 models (if you don't get into the variants within a model there are about 20 different machines that have a TRS-80 logo) but I do have a Model 1, III, 4 and 4p - the classic Radio Shack Z80 machines.

Re: What era did power supplies become switching?

PostPosted: Thu Jun 16, 2016 12:38 pm
by takintosh
tezza wrote:That's a good question, but one I don't know the answer to myself. I imagine some Googling research will supply the answer but yea, I imagine the change happened around the late 70's/early 80s.


I would say in the 8os. Then it some what happened again in the 2000s. Especially when Mac started gaining popularity.