posted by [1]hubie on Thursday March 21, @11:49PM [2]Printer-friendly
[3]Hardware
[4]
https://www.righto.com/2012/02/apple-didnt-revolutionize-power.html
The new biography Steve Jobs contains a remarkable claim about the
power supply of the Apple II and its designer Rod Holt:
Instead of a conventional linear power supply, Holt built one like
those used in oscilloscopes. It switched the power on and off not
sixty times per second, but thousands of times; this allowed it to
store the power for far less time, and thus throw off less heat.
"That switching power supply was as revolutionary as the Apple II
logic board was," Jobs later said. "Rod doesn't get a lot of credit
for this in the history books but he should. Every computer now uses
switching power supplies, and they all rip off Rod Holt's design."
I found it amazing to think that computers now use power supplies based
on the Apple II's design, so I did some investigation. It turns out
that Apple's power supply was not revolutionary, either in the concept
of using a switching power supply for computers or in the specific
design of the power supply. Modern computer power supplies are totally
different and do not rip off anything from Rod Holt's design. It turns
out that Steve Jobs was making his customary claim that everyone is
stealing Apple's revolutionary technology, entirely contrary to the
facts.
The history of switching power supplies turns out to be pretty
interesting. While most people view the power supply as a boring metal
box, there's actually a lot of technological development behind it.
There was, in fact, a revolution in power supplies in the late 1960s
through the mid 1970s as switching power supplies took over from simple
but inefficient linear power supplies, but this was a few years before
the Apple II came out in 1977. The credit for this revolution should go
to advances in semiconductor technology, specifically improvements in
switching transistors, and then innovative ICs to control switching
power supplies.
__________________________________________________________________
[5]Original Submission
References
1.
https://soylentnews.org/~hubie/
2.
https://soylentnews.org/print.pl?sid=24/03/20/0130231
3.
https://soylentnews.org/search.pl?tid=9
4.
https://www.righto.com/2012/02/apple-didnt-revolutionize-power.html
5.
https://soylentnews.org/submit.pl?op=viewsub&subid=62353
