I have an NMOS with me so I tried to design this 12 V DC UPS circuit after looking at another similar PMOS circuit, but when I open the dc switch, the output is 18kV!! What is the problem with this circuit?
I remove a pull-down resistor, and now there is no simulation error. I also tested it on the breadboard and it seems to be working with a 9V battery. I have yet to buy a 12V battery.
My apartment has an automatic generator backup (yay!), but the power goes down for around 10s before it powers up. A similar thing happens when the power comes back online. On a few days there is a large number of power cuts and comebacks. I use a direct fibre router which takes around 3-4 mins to start up and so I wanted a circuit like this. The router uses 12V power, so I plan to use a non-rechargeable or small lead-acid battery.
Similar PMOS circuit:
P channel mosfet battery charging/power selection circuit help
Circuit I made:
Multisim Live: 12V DC UPS