[time-nuts] Power supply for OCXO using "USB power blocks"

[jimlux]

On 3/10/19 12:07 PM, Achim Gratz wrote:
> jimlux writes:
>> How quiet is the output from those USB battery things..I've used one
>> to run a RTL-SDR, but that's hardly a ultimate low noise receiver.
> 
> Depends, but I suspect that most of them favor cheap over quiet -- they
> do already have a DC-DC in there that gets whatever the accumulator
> voltage is to 5V.  I also have one of these that is really noisy when it
> has no load, but seems to be OK when I start pulling a few mA.
> 
> Plus, chaining DC-DC like you outline really isn't helping efficiency
> wise.  Unless you already have a bunch of USB power banks you want to
> reuse (I'd still think about just using the cells then), perhaps have a
> look at some of the stuff that the RC model crowd is using.




it was the idea of reuse of the ubiquitous USB 5V sources, whether line 
powered or battery powered.