Idea DC-DC converter step up from usual power bank as external battery for nikon DSLR

Can anybody build a circuit to convert the 5v-2.1A to 8.4v-2.5 to be able to power on the DSLR camera

USB output 5V*2.1A=10.5W
Camera input 8.4V*2.5A=21W

The idea inspired from ifootage Electric Ray E1  ,I don't believe in would power on my DSLR nikon D7100 probably, plus it's too expensive for me 

Downunder35m6 months ago

Might be a stupid question but do you suggest to find the missing 10.5W?
Last time I checked my electronics skills I failed to generate power sufficiently from thin air ;)

assem555 (author)  Downunder35m6 months ago

:D :D yup,I don't know how ?that's why i am asking?

there is an industrialized solution and they found the missing 10.5W ,so I hope that someone could bring DIY project as well

could you advise and help me :D