Quote:
Originally Posted by Argus25
I have just completed a 21 page document on this switch-mode supply from the early 1980's. IBM did not publish data on it.
http://worldphaco.com/uploads/The_IB...WER_SUPPLY.pdf
It contains a range of different circuit innovations including surge limiters that use a PUT, current detectors with a current transformer, modulated base drive for the switching transistors with current feedback to improve efficiency. |
Hey Hugo,
That's another monumentally detailed piece of investigation, primary research and documentation. Thanks for making this contribution. I had never thought that viable, robust SMPS existed as early as this and it is high-powered and quite intricately thought out.
I looked at the overcurrent sense arrangements with particular interest. Really interesting to see the two conditions you describe:
*overcurrent AND
*final Vout, supply, > specified limits.
That's really ingenious. I also note the inrush limiting arrangement. I've never seen or heard of a programmable unijunction transistor before - really interesting to see an unfamiliar variant of a very useful circuit.
Cheers!