This mini ups circuit provides power to operate 12V, 9V and 5V DC-powered instruments at up to 1A current. The backup battery takes up the load without spikes or delay when the mains power gets interrupted. It can also be used as a work bench power supply that provides 12V, 9V and 5V operating voltages
Circuit diagram of the paralleled three-phase three-level
Designing an Online UPS - (Part 11/17)
shows a detailed circuit diagram of the UPS reported in [6]. The
12V 600VA Inverter Project Using a Transformer Salvaged From UPS Electronic circuit projects, Electrical circuit diagram, Electronic schematics
UPS Selection Factors for a Control System - InstrumentationTools
UPS Circuit Diagram with Repair and full Working Tutorial
Mini UPS with battery buffer
3 Simple DC UPS Circuits for Modem/Router - Homemade Circuit Projects
Integrating uninterruptible power supplies (UPSs)
batteries - Mini-UPS schematic - load-sharing of battery pack and power source - Electrical Engineering Stack Exchange
Mini UPS System Detailed Circuit Diagram Available
Small UPS circuits diagram, 6V-7V backup - EasyEDA open source hardware lab
Liebert PSI5 Lithium-Ion UPS - 1500VA 1350W 120V, Line Interactive AVR Mini Tower Sine Wave UPS, 0.9 Power Factor Uninterruptible Power Supply(Battery Backup) with Surge Protection(PSI5-1500MT120LI) : Electronics
What is and how does uninterruptible power supply (UPS) work?
DIY Mini UPS for WiFi Router / Modem : 12 Steps (with Pictures) - Instructables