I have a D-Link DNS-323 Network Attached Storage box which, according to the specifications sheet has a maximum power draw of 21.04w and a sleep mode power draw of 10.45W. The switch mode PSU it comes with has two voltage outputs, 12v/3A and 5v/3A.
As it is on all the time (with a duty cycle of around 35-40%) I would like to see if it's possible to run it from two 8W solar panels through a storage battery.
I have several "yuasa" sealed lead acid batteries and I'm thinking of using a 20AH 12v as the storage battery.
Given that the duty cycle is less than 50%, using my sketchy mathematics skills I'm assuming that 16W of solar cells should be sufficient to keep the battery charged?
If this is correct, I assume need to make a circuit that will regulate the charge current for the battery - I have no idea how to do this other than with something like an LM7812 voltage regulator?
The next thing I need to do is convert the output of the battery into 12v and 5v rails for use with the NAS box. I notice that the 7805 and 7812 regulators have a max current rating of 1A... my concern being that the manufacturer of the NAS box thought it prudent to give both rails a 3A output which exceeds this components maximum rating.
What other devices are available for such a power converter and is it possible someone could help me out with a circuit diagram?
Thanks for reading!
As it is on all the time (with a duty cycle of around 35-40%) I would like to see if it's possible to run it from two 8W solar panels through a storage battery.
I have several "yuasa" sealed lead acid batteries and I'm thinking of using a 20AH 12v as the storage battery.
Given that the duty cycle is less than 50%, using my sketchy mathematics skills I'm assuming that 16W of solar cells should be sufficient to keep the battery charged?
If this is correct, I assume need to make a circuit that will regulate the charge current for the battery - I have no idea how to do this other than with something like an LM7812 voltage regulator?
The next thing I need to do is convert the output of the battery into 12v and 5v rails for use with the NAS box. I notice that the 7805 and 7812 regulators have a max current rating of 1A... my concern being that the manufacturer of the NAS box thought it prudent to give both rails a 3A output which exceeds this components maximum rating.
What other devices are available for such a power converter and is it possible someone could help me out with a circuit diagram?
Thanks for reading!