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GTR2Fan
Posts: 1601
Joined: Sun Feb 23, 2014 9:20 pm
Location: South East UK

Re: Safe shutdown - Simple way

Thu Apr 24, 2014 1:06 pm

I don't understand why you want to use super-capacitors in the first place. Have you looked at the price of them compared to something like this which would also work as a UPS for a fraction of the cost?
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

surfparadise
Posts: 95
Joined: Fri May 10, 2013 9:01 am

Re: Safe shutdown - Simple way

Thu Apr 24, 2014 1:21 pm

GTR2Fan wrote:I don't understand why you want to use super-capacitors in the first place. Have you looked at the price of them compared to something like this which would also work as a UPS for a fraction of the cost?
I don't think that it's really expensive… (I need only 2…5F could be enough), and the battery of the UPS are not durable like a capacitor.

http://www.ebay.com/itm/350965686739?ss ... 1423.l2649

Below the new version… I forgot a resistor…. :-D

https://dl.dropboxusercontent.com/u/275 ... ircuit.jpg


Regards,

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GTR2Fan
Posts: 1601
Joined: Sun Feb 23, 2014 9:20 pm
Location: South East UK

Re: Safe shutdown - Simple way

Thu Apr 24, 2014 1:38 pm

Oops! My mistake! Somebody else was asking a similar question recently and I think they were looking at 2700F capacitors like these. :D
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

Paul Moir
Posts: 46
Joined: Wed Dec 04, 2013 7:25 pm
Location: Nova Scotia, Canada

Re: Safe shutdown - Simple way

Fri Apr 25, 2014 6:51 am

If you look closely at a supercap's specs, they are not exactly durable. Esp. at elevated temperatures.
No free lunches I'm afraid...

surfparadise
Posts: 95
Joined: Fri May 10, 2013 9:01 am

Re: Safe shutdown - Simple way

Mon Apr 28, 2014 3:32 pm

@Hampi

Could you check if this new version could works?

I have to add a pull up resistor on the logic input1 of tiny85 ??

Thanks

slado
Posts: 21
Joined: Thu Aug 16, 2012 6:23 am

Re: Safe shutdown - Simple way

Fri Aug 15, 2014 9:51 pm

I am working on a similar project using supercapacitors for powering the RPI while shutting down:

www.juice4halt.com

I have used 2x25F/2.7V supercapacitors. This is enough for supplying the RPI (average current 375mA) for about 60 seconds. The supercapacitors are discharged from 5V down to 1V. For other currents download the datasheet. At the end is a table showing all the times vs. currents.

jaybmate
Posts: 1
Joined: Tue Jul 07, 2015 5:52 am

Re: Safe shutdown - Simple way

Tue Jul 07, 2015 5:54 am

Did anyone actually do this and get this working?

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