External 5V power supply for FDM-S2


walkabout creek
 

I would like to operate FDM-S2 on a tablet with external 5V power supply. For this I have to reduce the power consumption on the tablet. Is there a way to connect the FDM-S2 to an external 5V power supply? If so, what are the possibilities?

73, Willi


Giovanni Franza
 

Hi Willi,
the easiest way is to use a powered USB HUB.
Regards,

Giovanni - HB9EIK


Willi Westrupp
 

Hi Giovanni,
when the powered USB hub is connected to the FDM-S2: does the FDM get power only from the USB HUB?
How can I check this?
I ask that because the USB power line from the tablet in this case is not interrupted. I have to try to reduce the power consumption on the tablet. Another possibility would be to branch off the two USB power cables on the socket and hang them on a longitudinally regulated power supply. Has anyone done that and did it work?

73, Willi


Am 24.02.2018 um 10:10 schrieb Giovanni Franza:

Hi Willi,
the easiest way is to use a powered USB HUB.
Regards,

Giovanni - HB9EIK


  


Bjarne Mjelde
 

You have probably ruled out switching power supplies already, which is a wise thing to do.

Possible sources:
1. Lithium battery power bank (usually marketed for charging cell phones). Will only last "so" many hours though. Here is my test of one.
2. "Amateur-grade" linear power supply, such as the Diamond GSV-3000 (possibly overkill in your setting, but still).
3. Lab-grade linear supplies, like those from Bel Power Solutions.

I've tried all of the above for various SDRs, and they all work. The Bel Power is surprisingly cheap, and I would recommend it. A discussion of ways to power your SDR (in this case the Perseus) is here
The S2 power consumption is only marginally higher than the Perseus.

There were linear (transformer-based) wall warts available in Europe some years ago, but I believe they are gone due to EU regulations.

Bjarne Mjelde
arcticdx.blogspot.com


Giovanni Franza
 

Hi Willi,
since S2 has a power led, you can see the led glowing when you connect the S2 to a powered USB HUB, so the power arrives from the power supply attached to the USB HUB.
I'me quite sure that, once powered from its supply, the HUB doesn't drain power from yout tablet, also you can attach mouse and keyboard to this HUB to further reduce power drain from tablet.
To be sure making mesaures there exists some USB digital power monitors available from Cina, but I haven't tested any of them.
Regards,

Giovanni - HB9EIK