[time-nuts] Need help with transformer core
EWKehren at aol.com
EWKehren at aol.com
Sun Aug 31 11:29:08 EDT 2014
Thanks for the reply in all applications the DC DC converter is used for
isolation and followed by linear regulators. In critical stages like dual
mixer two stages.
Bert
In a message dated 8/31/2014 11:12:18 A.M. Eastern Daylight Time,
attila at kinali.ch writes:
Hoi Bert,
On Sun, 31 Aug 2014 07:15:02 -0400 (EDT)
Bert Kehren via time-nuts <time-nuts at febo.com> wrote:
> Any opinion or observation on Mean Well's SD series, they are a key
> component on most of our projects.
I never had the pleasure to measure any of the Mean Well DC/DC converters.
Looking at their spec, they seem decent enough. The ripple and load
regulation specs are not exactly time-nut class, but not unheard of
for this kind of brick, isolating DC/DC converters. Also a nice feature
is the CE marking, resp the EMC emission specs, which a lot of cheaper
devices do not have. Unfortunately, they do not mention which class
of the EN55022 they comply to. It's probably Class B, but not necesarily.
[1]
What i'm missing is a specification of the switching frequency, that would
help to guide the filter needed at the output. But i'd assume it's
something in the range of 100kHz-500kHz, definitly less than 1MHz at
these power ratings.
Such brick converters are usually used as a first stage converter to
power a complete system from some industrial or telecom power rail.
As such, they are meant to have a second stage regulator infront of
the electronics (or electronics that can cope with the ripples and
flucutation of the power rails, like slow digital logic).
Ie. i recommend to use another, specialized DC/DC converter or LDO
infront of your electronics, to keep the power more stable and have
less ripple.
As for use with an FE-5680A, i guess these DC/DC converters are good
enough, as the FE-5680A has its own internal regulator.
HTH
Attila Kinali
[1] A little warning here. The normal way how such devices pass the
EMC/EMI tests is by constructing a still realistic circuitry around
it, that modifies the devices behaviour enough that any non-compliance
is mitigated. Unless you measure these devices with a realistic model
of your system, or the system itself, you cannot be sure that the
DC/DC converter still passes the EMC regulations.
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