A question came up on Youtube.com – http://www.youtube.com/watch?v=TDGYIUZMbuY about why the old Imsai 8080 Computer used a big power transformer and beer can sized capacitors in its power supply.
Before answering that comment I went looking for Computer Power Supply History and found this:
This seems to be a very good article on Computer Power Supply History even though it starts out countering claims by Steve Jobs that the Switching Power Supply in the Apple II was revolutionary. It goes on to explain that switching power supplies have been around for a LONG TIME … but the bottom line being that the jump to transistors that could handle the Line Voltage (110vAC?) directly without a power transformer was the biggest.
The comments below the article were also interesting (including one back from the article author) – I liked #4 comment about Power Waste as Heat and Efficiency … complete with the pertinent calculations.
Alan Spicer Marine Telecom and WiFiYacht.net
communications @ marinetelecom.net
“I always thought of myself as a humanities person as a kid, but I liked electronics. Then I read something that one of my heroes, Edwin Land of Polaroid, said about the importance of people who could stand at the intersection of humanities and sciences, and I decided that’s what I wanted to do.”
%%% Steve Jobs, from Walter Isaacson’s biography.
* Alan says: That quote from Steve Jobs is interesting to me because of similarities to myself. I had a photo of myself tagged (written by hand on the back or was it the front? I’ve got to find that photo again) by my mother for me as being “A politician”. I don’t remember what got written for my two brothers … but it was supposed to be sort of a prediction of what her sons would become. That picture was probably 30 years ago.
I also liked electronics and communications, and especially electronics that facilitated or performed the function of communicating. I was inspired by my grandfather who had been in the electrical field (Edison Electric Co. Chicago) and radio field (supposedly had his own radio shop and built radios, though I never saw that in person.) My grandfather did give me the radio “bug” and he showed many radio and communications things to me and my brothers. We were fascinated by his reel-to-reel tape recorder among other things. My grandfather gave me an old shortwave radio – it was a tube type receiver with the “XX Meter Band”‘s marked on it. I remember listening to HCJB - Quito, Ecuador among other signals such as VOA – Voice of America. I went in the Navy at 17 as a Signalman (Flags, Semaphore, Morse Code by Light) and also qualified on my own as a Radioman. I did perform a health-and-welfare communications role onboard ship during my last year by activating a SSB Radio based system (Navy MARS) that allowed Radio-Telephone “Patch” Calls for the officers and crew. But I don’t know if I did that more as a humanities thing or for the pure enjoyment of being able to operate the ships powerful radio transmitter and receiver equipment. I did enjoy both the human goodwill and the radio – electronics part of it.
I like to think of myself as a person that, through my work in computer and communications consulting, brings down to earth (in laymans terms)the technologies involved in computers and communications (ala “The Internet” and “Voice Telephony” these days.) I have a love for providing documentation and learning and knowing how stuff works and passing that on to friend and customers. I like to know at least a moderate if not a great deal about how computers and communications devices work. I also like fashioning better ways of doing things, easier to use, and to my benefit easier to support. Anyway I’m not Steve Jobs … but I am Alan Spicer.