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I have a remote control for a GoPro camera. The remote runs off a 3.7 v li-ion battery. The remote draws about 100 mA.

I want to extend its usability by supplying 12 v power. The camera cable takes 12 v power then has its own converter cable that plugs into its bus port to supply 4.2 v. I have a separate power line off the 12 v that inputs to an eBay dc dc buck converter set at 4 v. I have removed the battery and the buck converter (LM2596) is soldered in its place. I removed the battery since it is no longer needed and space was an issue.

schematic It seems to work well, however I'm wondering whether I can expect any reliability issues, or whether this is not good practice. FYI, i tried running both camera and remote off the camera converter cable but this does not work.

Thanks a lot.

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  • \$\begingroup\$ Could you add a schematic? It's a little bit difficult to understand what's connected to what. \$\endgroup\$
    – uint128_t
    Feb 10 '16 at 1:23
  • \$\begingroup\$ Ask the eBay seller about reliability of his buck converter. While you are at it, also ask for the datasheet and a schematic. \$\endgroup\$ Feb 10 '16 at 1:37
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    \$\begingroup\$ Ok thanks. Schematic added. Part number is LM2596 \$\endgroup\$
    – UW2014
    Feb 10 '16 at 1:47
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I would first try to run just the remote off the buck converter and the 12V supply to see if it works. Then you will know if that setup works. Then, what about the power supply can handle both loads? you may need a higher rated supply to run both.

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The LM2596 itself (minus the other components on the eBay module you bought) is rated for up to a 3A load.

As long as your eBay supplier used quality components, and its voltage stability is acceptable (luckily, most battery-operated devices are fairly forgiving here), you should actually be able to run both the remote & the goPro from just the LM2596. :)

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  • \$\begingroup\$ Thanks Rob. I thought that as well but doesnt seem to work. Buck converter is rated to 2 A so should be ok. There must be something in the camera battery eliminator circuit that isnt replicated on the buck converter. \$\endgroup\$
    – UW2014
    Feb 10 '16 at 2:17
  • \$\begingroup\$ Hmmm...if the LM2596 is rated 3A & the circuit you bought is only rated 2A, there's a likelihood the eBay seller's supplier used some cheap parts that interfere with the primary component's ability to maintain an accurate voltage. You may want to try hooking a volt meter to the buck converter's outputs & see exactly how accurate/stable its voltage control really is. \$\endgroup\$ Feb 10 '16 at 2:27
  • \$\begingroup\$ Seems to be very stable. Maintains 4 v through operation and start up/shutdown \$\endgroup\$
    – UW2014
    Feb 10 '16 at 22:17
  • \$\begingroup\$ @Sxuv ok, then at least it should be stable/safe enough to not harm your remote much :) \$\endgroup\$ Feb 11 '16 at 1:19

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