Category Archives: Old School Tech

Heirloom Blueberry Cuttings, Part II, The Cuttings

Old School Tech continues its heirloom blueberry cuttings series, this time about preparing and soaking the cuttings themselves. Although this experiment deviates a little from normal cuttings techniques, it appears to be producing promising results so far. As mentioned last week, we had great results a couple of years ago from these same plants. This […]

Heirloom Blueberry Cuttings, Part I, Background

Old School Tech has released an article introducing a new series on heirloom blueberry cuttings. This project is simple, uses simple materials, makes a great homeschool earth science project, and can create a large number of new plants from a single shoot. As the article mentioned, we had the material for hundreds of new cuttings […]

Double Conversion UPS Update

Old School Tech has released an update in the double-conversion UPS series. The latest article describes detailed test results with two different loads, one load more than twice the nominal rating of the batteries, and the other much less than the nominal rating. What emerges from this latest article is a rule of thumb to […]

Food Storage Jar Seals

OldSchoolTech has released an article on 3D printing seals for those wire-closure glass food storage jars. This was a fun project for NinjaFlex, which is a flexible, rubber-like material useful for making low-temperature gaskets and seals of all kinds. Our 3D printer also has a dual head, which allows plastic and flex to be printed […]

Double Conversion UPS, Part I

After a long hiatus, Old School Tech has posted the first article in a new series, this time about creating a double-conversion uninterruptible power supply, which is useful for driving loads such as freezers or mission-critical items. Like a computer UPS, this power supply waits, fully-charged, until it is needed. Unlike a computer UPS, however, […]

Multicolor Off-Grid Christmas Lights

Old School Tech has released the final article in the off-grid Christmas light series, this time with a discussion about multi-color lights, their analysis and a useful generic design procedure. Homeschoolers will find a nice wrap-up in this article with a more scientific process that makes a great science project, linking science, electronics and statistics. […]

Red Off-Grid Christmas Lights

Old School Tech has published the latest in their off-grid emergency lighting series, this time on the adaptation of red LED Christmas lights for off-grid DC operation. Red LEDs have an important application to community defense purposes, in that they help preserve night-vision. As such, they are uniquely useful for use in an operations center […]

Extracting Potash

Old School Tech has released an article about extracting raw potash from wood ashes. Future projects will refine and use this raw product for interesting things. Not only does this project make a great homeschool chemistry lesson, it also sets the stage for some chemical processes of interest to self-sufficiency enthusiasts. As mentioned in that […]