This is probably the first project I’d done and it was when I worked at Mostek. I used a piece of scrap perfboard, some TTL ICs and sockets, and a few Old Style LEDs – big, old, current-consuming, 1982, RED LEDs. And some wire-wrap wire – it was all I could find, so that’s what I worked with.
The circuit is from Don Lancaster’s “TTL Cookbook”. It has worked for years and years, and uses almost any 6 to 9 volt Wall Wart. Unfortunatly, about 10 years ago a wire or two came loose from underneath (a rats-nest of misused wire-wrap). I finally got around to fixing it and actually replacing a rare burned-out LED.
I have no idea why I chose Wire-Wrap wire, other than it was something we had laying around or scrapped. It’s some of my earliest, gloppiest examples of soldering that I have. Wish I had that old Radio Shack P-Box that I build back when I was about 12.
Built one of the ubiquitous ‘Desktop Power Supply’ from a recycled, ATX-form, PC power Supply. Actually used it occasionally to power a 12V charger in the garage. Unfortunately, it fizzled an electrolytic capacitor and it’s really not worth reparing.
So, I rescued all my hardware and built a reusable adapter for ANY standard ATX power supply.
1 ATX Power extender – this is an extension to the wide plug that goes to the motherboard, usually about 9 inches or so (like this one: http://www.directron.com/atxextension.html).
All of the other hardware bits needed to alter an ATX supply for desktop use (binding posts, a switch, a 10 ohm / 15 watt resistor (I used a Dale, metal-cased).
And an enclosure – a wide, thin, Radio Shack enclosure I had on hand.
The 10 ohm 15 watt resistor goes from the +5V rail to Ground. This is needed so that the supply can sense a load – otherwise, it will not start.
Mostly for personal use, this is in response to a posting on the ARF (AntiqueRadios.com Forums) regarding ‘how do you track what tubes you have’.
The inventory system keeps each user’s inventory separate, and draws from a common database of tube data (still building that common list, currently at around 450 tubes).
Some features include an ability to import from Excel (actually CSV exports from Excel), export back to Excel, print an inventory, keep (and print) a separate ‘shopping list’, and some searching facilities.
I added some small calculators to the ‘Software’ link. While rebuilding a Heathkit V-7 VTVM, I just couldn’t find a good match for a couple of out-of-tolerance precision resistors in the divider network. So I built my own: a) Toroid Calculator and b) Precision Resistor Calculator.