This is a DC Uninterruptible Power Supply (UPS) for router and printer using capacitors instead of battery.
It running the load for very short time (seconds) to solve the problem of ATS delay time.
Parts list:
Capacitor 150uF 450V or 400V (11pcs)
Resistor 100 ohm 25 watt
Resistor 100K 0.25 watt (2pcs)
LED 5mm
Diode 10A10
Bridge rectifier D35SB100
Connector HB-825
AC Fuse 10A
DC fuse 10A
Socket SS-801 (2pcs)
Circuit:
You can download the Gerber file of the PCB from PCBWay:
https://www.pcbway.com/project/shareproject/DC_UPS_for_Printers_and_WiFi_Routers_57e49864.html
Formula to calculate the running time depend on the load and size of the capacitors
C= capacity in farad
I= current of the load in amp
T= running time in second
V start = maximum voltage of the capacitor (rms x 1.4142)
V stop = minimum voltage before load turns off
NOTE: In LED light bulbs the current (I) is almost constant in any voltage due to constant current driver used in most LED bulbs which make it easier to calculate the running time, But for other loads with constant voltage driver this formula could gives inaccurate results.
Watch this Video for more Details:
