At 07:38 PM 3/9/2019, jimlux wrote:
Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V
from one of those rechargeable USB power bricks. I was thinking
about portable operation.
My USB power bricks shut off the 5 V output if there's not enough
load. Something to watch for.
Let me try it. I have a few of those 5V USB power supply. I have on my desk,
DC/DC converter that will take whatever to whatever. Got a dozen from Amazon.
I'll set it to 12V. I'm sure it will work in some fashion. I've used unknown
power supply (switching type) for various things, and I
Jim said:
The question is really more one of "how much filtering do I need to
design into the downstream power supply circuits"
The answer of course depends on the source and receiver of the noise.
Common USB type systems and accessories are built to maximize cheapness,
pass EMC testing well
Hi
Part of the problem is radiated / mag coupled spur energy. One of the things
that
makes the fancier switchers more friendly is that they can contain this better.
Bob
> On Mar 10, 2019, at 12:10 PM, jimlux wrote:
>
> On 3/10/19 8:58 AM, Richard (Rick) Karlquist wrote:
>> Check out the
On 3/10/19 8:58 AM, Richard (Rick) Karlquist wrote:
Check out the LT3045-1.
Ive used the LT3042 in a space application, it is basically the same
thing with lower output current. The really great thing is that the
rejection extends up to 10 MHz.
It is an ultra low noise (2nv) linear
Am 10.03.19 um 15:54 schrieb jimlux:
True.. but there are a plethora of the USB 5V power blocks around - in
general, there are lots of USB 5V (noisy, I'm sure), e.g. Cars now
have 5V USB jacks, so I was thinking about designing with that in mind.
The question is really more one of "how much
Check out the LT3045-1. It is an ultra low noise (2nv) linear
regulator with very high PSRR that has a 1 MHz bandwidth.
The -1 version can control an external switcher (or linear)
regulator ahead of it, where the voltage drop across the
LT3045-1 can be set to, say 1V, and the front end supply
with the latest versions.
Bob
From: jimlux
Sent: Saturday, March 9, 2019 9:00 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Power supply for OCXO using "USB power blocks"
Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V from
on
On 3/9/19 7:42 PM, Gerhard Hoffmann wrote:
Am 10.03.19 um 01:38 schrieb jimlux:
Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V
from one of those rechargeable USB power bricks. I was thinking about
portable operation.
In my case, the OCXO is something like a Wenzel
Nortel GPTM operates on 24 or 48V DC. Internally, there is a step down dc/dc
converter and 3 terminal regulators. It creates whatever it needs internally.
So it can be done. It does have quite a bit of filtering though. I have run
Oven oscillators with a regular cheap switcher. Spec says
Am 10.03.19 um 01:38 schrieb jimlux:
Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V
from one of those rechargeable USB power bricks. I was thinking about
portable operation.
In my case, the OCXO is something like a Wenzel streamline. I would
think that the DC/DC
Usually they are very noisy, with the noise rising rapidly with load current.
goughlui.com, lygte-info.dk, and a few others have published some tests. I
think bigclive has also done some tests.
--
> How quiet is the output from those USB battery things..I've used one to
run a
Has anyone tried a +5V to +15V DC/DC to run an OCXO, getting the 5V from
one of those rechargeable USB power bricks. I was thinking about
portable operation.
In my case, the OCXO is something like a Wenzel streamline. I would
think that the DC/DC probably has some noise, but maybe DC/DC to a
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