Projects from my workbench

Auto Start for UPS3v2 UPS  1. Introduction    This project shows how to use an ATTiny microcontroller to restart a UPS3v2 after it has been automatically shutdown due to a lightning storm detection event.  The ATTiny is included as part of the Disconnector 1 board that separates a UPS from wallpower in the event of a lightning storm.    We know that we cannot provide complete protection from a lightning strike.  Lightning will have its way with your home, appliances, and electronics.  It cannot be prevented.    But, you can protect from damaging surges caused by nearby lightning.  You should have a whole house lightning/surge protection such as this one from SECO.   Also, you should install surge protective devices at each outlet where sensitive electronics may be installed. I like this one from Amazon.  This device from APC also works well. 2. Description    Once you've implemented SPDs, ...

Uninterruptible Power Supply for Raspberry Pi    This is a blog to share my UPS project.  You'll see pictures, code, schematics, and test information.  I have never written a blog before so good luck to me! Introduction    This uninterruptible power supply was designed to provide operating power to a Raspberry Pi (RPi) computer.  It uses a diode switch  to select wall power if available, but switch to battery backup automatically should there be a power failure.  Battery voltage is supplied by 8xAA Nickel-Metal Hydride batteries.  To ensure that power will be available, I selected Tenergy brand Centura Low Self Discharge cells, such as these available from Amazon.  They are intended to maintain charge over long periods of storage.    The Tenergy AA size battery has built in low self discharge technology that prevents it from losing its power after long storage periods. Once charged, it can be stored for 12-2...