Author Topic: diy 12V ups questions  (Read 1010 times)

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Offline Diyaudio_enthusiast

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diy 12V ups questions
« on: October 20, 2021, 01:11:14 pm »
Good day members

I'm making a small 12V ups for routers,modems etc..
Main power supply is a 12V 2A wall power adaptor.
Secondary power supply is a single 18650 connected to tp4056+voltage boost module.
I'm planning to use IRF9530N p channel mosfet for switching.
I've attached a rough schematic to show the connection.
Please let me know about possible issues with this arrangement.
Thanks
 

Offline Vovk_Z

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Re: diy 12V ups questions
« Reply #1 on: October 21, 2021, 08:06:16 pm »
Why do you need a switch?
 
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Offline Diyaudio_enthusiast

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Re: diy 12V ups questions
« Reply #2 on: October 24, 2021, 12:36:51 pm »
Why do you need a switch?

to switch between wall adaptor & battery (when mains power down)
 

Offline ogden

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Re: diy 12V ups questions
« Reply #3 on: October 24, 2021, 02:46:56 pm »
 
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Offline Vovk_Z

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Re: diy 12V ups questions
« Reply #4 on: October 25, 2021, 07:13:37 am »
The switch can be eliminated choosing the right voltage for the charger.
Doy you reaaly need to switch between them if you have protective Shottky (or other type) diodes?
« Last Edit: October 25, 2021, 07:15:17 am by Vovk_Z »
 
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Offline JohanH

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Re: diy 12V ups questions
« Reply #5 on: October 25, 2021, 04:15:36 pm »
I've had a stupid charger/powersupply adjusted to 13 V connected to a small 12V lead battery for 6 years now, driving router, wifi access point, network switch, modem and a raspberry pi (using a 12V to 5V DC converter) for 6 years. Foolproof and no circuitry needed.
 
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Offline Vovk_Z

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Re: diy 12V ups questions
« Reply #6 on: October 25, 2021, 08:32:35 pm »
I'm talking about the same.
 
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Offline Diyaudio_enthusiast

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Re: diy 12V ups questions
« Reply #7 on: October 28, 2021, 08:32:33 am »
Thanks all for the input
Mains supply is quite unstable here.
When there is repair, we wont be having any power for 8 hours.
I'm using this as a learning experience too.
 

Offline HB9EVI

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Re: diy 12V ups questions
« Reply #8 on: October 28, 2021, 12:33:11 pm »
like the others said, the easiest way is to build an adjustable power supply, set it on ~13-13,8V (which is no problem for common 12V devices) and hold a Pb battery in parallel on float charge.

Calculate the current drain from your devices and choose an appropriate Ah rated Pb-battery and you're fine to go also for longer than 8h
 
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