1
\$\begingroup\$

I have a filter that has these on it:

Funk-Entstörfilter    
Drossel    
250V~2A HPF F11.180/4    
8.84 W Germany 565-3

Front Back

I also added a picture. In the picture, you can see that there is a circuit diagram, however I can't understand this diagram. In example, how the capacitors are connected? Do these lines that connects inductors mean that they are coupled? I don't know much about it but can they be common mode chokes?

Can you convert this into a schematic that I can understand?

\$\endgroup\$
4
\$\begingroup\$

Funk-Entstörfilter = RFI suppression filter
Drossel = Choke

The lines connecting the top and bottom coils indicate that they're coupled, i.e. wound on the same core, often a toroidal core. The strange capacitor symbol indicates a double capacitor, 2400pF from either side to ground (you have to connect ground for the filter to work properly)

Note: the German word "Funk", meaning radio; refers to "spark" ("Funke"), which derives from the first wireless application: the telegraph.

\$\endgroup\$
  • \$\begingroup\$ Thanks @stevenvh, admire your eager to languages :) Ah btw, is it possible that you show the capacitors with a circuit diagram? And by ground, do you mean the chasis or such? One more, what would happen if I don't connect the chasis? \$\endgroup\$ – abdullah kahraman Oct 4 '11 at 10:01
  • \$\begingroup\$ @abdullah - The capacitors are simply in series between line and neuter, with the common point connected to ground (chassis). If you don't connect ground the interference just flows from line to neuter and vice versa. Connecting the ground to chassis actually drains this interference. \$\endgroup\$ – stevenvh Oct 4 '11 at 10:20
  • \$\begingroup\$ There is no chassis connection in the bus. Plus, this is a DC line. So does this make this filter useless? If so what kind of filters would you recommend? \$\endgroup\$ – abdullah kahraman Oct 4 '11 at 10:39
  • \$\begingroup\$ @abdullah - This is a mains filter, to be used at the power input for mains operated devices. Why would you use this particular filter? \$\endgroup\$ – stevenvh Oct 4 '11 at 10:49
  • 2
    \$\begingroup\$ I agree that the inductors are CM. The caps could be Y (line / neutral to earth) or X (line to line). It is possible that the Y-capacitors are connected to the metal can and that the tab is meant to be an external earth connection. I see six capacitors in the textual description, so they could be a mix of X and Y. \$\endgroup\$ – Adam Lawrence Oct 4 '11 at 17:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.