Category Archives: Old School Tech

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 preppers, in that they help preserve night-vision. As such, they are uniquely useful for use in an operations center or an […]

Testing Emergency Solar Christmas Lights

Old School Tech has released a new article in the emergency solar Christmas light series, a topic of interest to preppers who need a little bit of extra light in those dark corners but don’t want to use valuable inverter capacity. This time, an easy-to-make test fixture is described which overcomes the quality problems often […]

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 preppers. As mentioned in that article, […]

Emergency Solar Christmas Lights

Old School Tech has posted an article about converting Christmas LED light strings into emergency DC lighting for use directly from an off-grid battery array, no inverter required. This kind of lighting is great for safety-critical areas and allows a reliable backup source of lighting when other sources fail. Annoying AC flicker is also eliminated. […]

Freezer False Alarm

Old School Tech has posted a new article about a little scare we had with our freezer this morning. Although it turned out that this was just a simple thermodynamic misunderstanding, it does help highlight some of the issues involved with debugging appliances.

Ground Solar Part VI, Wiring, Connectors and Tools

Old School Tech has released a new article, this time on solar wiring, connectors and tools. Although this is the final article in the hurricane ground solar series, it isn’t our last article on solar. This past week, we interviewed a system designer at Iron Edison about their nickel iron and lithium iron phosphate batteries; […]

Ground Solar, Part V, The Batteries

Old School Tech has released a new article in its ground solar series, this time about the batteries. Originally intended to only run a freezer, we were able to also run two refrigerators off this system, but only for about four hours per night. One of the missions of the nightwatch during the hurricane power […]