Tim’s Old Switching Power Supply for the Amiga Computer, with protections.
Input: 12VDC; Outputs: 5V@4A, 12V@0.5A.
Frances and I have written elsewhere about living out of our VW Beetle (with its giant roof rack) prior to and into the summer of 1984, of looking to move up into a funky camper van, of finding just the ticket, and of living in it for five adventurous years while putting 100,000 miles on it the honest way. We still have the van, “Emma,” she named it, after her favorite grown-up as a child, her grandma. But Emma doesn’t run anymore, and some of the technical features and touches that made it so cozy and functional are broken or missing. If we removed the tarp from the roof on a rainy day we would see if the leaks are worse than they were that night in Illinois, en route to New York, when 14-year-old Jason yelled, “Don’t stop on Elm Street!” and we placed pots and pans to catch the drips that punctuated our sleep. If we put in a charged battery, we could find out if the little Tripp Lite PV-400 inverter still provides 120 volts. But the awesome and trusty Amiga is long gone, and the custom power supply I designed and built for it, as a far more efficient conversion of car battery energy to volts and amps for the computer than the Tripp Lite could offer, went into the trash this very day, after a long denouement in a box in the garage, waiting for something, maybe a recognition of it as the condensation of a dream, a purpose backed by thought and persistence half a lifetime ago. The purpose was gone – along with the need – when we settled down in digs attached to the earth and got our first Pentium PC about 25 years ago. Over the following years we gradually recognized emotional attachments to physical things we had put ourselves and our concerted efforts into.
Another instance was the Quetzalcoatl model of my Celestial Fireplace series. The one I built for Frances and dedicated to her on her birthday in 1988, traveling with us in Emma during two trips around the country and over rugged terrain described elsewhere, amounting to a sustained vibration immunity test that it passed with nearly flying colors. But intermittent electrical faults became more and more common and disappointing. Until I could stand it no longer and dedicated the entire month of January a few years ago, every evening and weekend, to entirely rewiring the old prototype digital processor circuit board, meticulously following and checking against the tattered schematic I had drawn and saved years before. Lo and behold, upon reassembling, it worked perfectly on the very first power-up attempt. Moral of the story: not all physical artifacts to which we have emotional attachments to are doomed by the ravages of time to fail or fall out of use to the point of being relegate to the trash bin. Some things persist. And of course, Quetzalcoatl was a far, far larger project in concept, originality, development time, cost, labor, and eventual satisfaction.
Where and when was the old Amiga power supply born? Entirely before the World Wide Web was loosed upon the internet for everyone to share. Mostly in the set-up-and-use-as-needed electronics lab that good old Emma accommodated, with component data sheets, organized boxes of 1% resistors, assortments capacitors and ferrite transformer cores, soldering iron, oscilloscope, voltmeter, all the fixings. However, it was finished in the larger electronics lab that occupied a quarter of the tent that Frances and I set up near Emma where she was parked up in New Mexico’s Carson National Forest in the late spring of 1988. But that is another story.