2019-01-23, 10:58 PM
Hi Andy,
it is important to know if you have common or differential mode disturbers.
On a simple switcher 12 > 5 V and no RF transimission or high voltage output you
should have differential mode currents only.
This can be fixed with a LC Filter as described here:
https://www.we-online.de/web/en/electron...imiert.php
High voltage switcher have capacitive loads and some current is taking
the direct way to the ground. Because of this you get common mode currents on both
plus and gnd and all signal wires. > common mode choke
Same if you have a RF transmitter. Some energy is hopefully escaping via RF.
So the current is flowing over all, power and signal wires. > common mode choke.
For a simple switcher a differential filter, LC or just capacitors should be OK.
But I have no experience about LCD or TFT Panel. Maybe they require common mode
filter as well. I will have a phone call with wurth electronic about this.
They have application engineers locally and are very willing to help.
Best wishes,
Chris
it is important to know if you have common or differential mode disturbers.
On a simple switcher 12 > 5 V and no RF transimission or high voltage output you
should have differential mode currents only.
This can be fixed with a LC Filter as described here:
https://www.we-online.de/web/en/electron...imiert.php
High voltage switcher have capacitive loads and some current is taking
the direct way to the ground. Because of this you get common mode currents on both
plus and gnd and all signal wires. > common mode choke
Same if you have a RF transmitter. Some energy is hopefully escaping via RF.
So the current is flowing over all, power and signal wires. > common mode choke.
For a simple switcher a differential filter, LC or just capacitors should be OK.
But I have no experience about LCD or TFT Panel. Maybe they require common mode
filter as well. I will have a phone call with wurth electronic about this.
They have application engineers locally and are very willing to help.
Best wishes,
Chris