DC line filter/ suppressor

[Klaus]

The attached filter apparently does a good job to suppress the noise radiated from portable 12V fridge compressors which makes MW & SW reception almost impossible while the fridge runs.
The problem is sourcing the chokes, does anybody have the info on making one?
Thanks
Klaus

 

[Klaus]

The attached filter apparently does a good job to suppress the noise radiated from portable 12V fridge compressors which makes MW & SW reception almost impossible while the fridge runs.
The problem is sourcing the chokes, does anybody have the info on making one?
Thanks
Klaus

Oops, that attachment business is obviously not dummy friendly
Any special trick about it, its a .BMP file?

 

[bryan1]

The attached filter apparently does a good job to suppress the noise radiated from portable 12V fridge compressors which makes MW & SW reception almost impossible while the fridge runs.
The problem is sourcing the chokes, does anybody have the info on making one?
Thanks
Klaus

Oops, that attachment business is obviously not dummy friendly
Any special trick about it, its a .BMP file?

Eh Klaus,
I'm sure you have to change the format to .jpg or .png. png would be the best as the file is smaller and the clarity is much better than jpg's

Hope this Helps Bryan

 

[stevez]

Klaus - Amidon Associates is where I'd check for cores. They deal in small quantities and provide lots of technical information. Palomar might be another.

The local electronics shop had these nice toroidal coils made for just that kind of duty - two windings, one on each side of the form with #14 wire which is good for 15 amps. They were $4 US. I grabbed one. They might still have some. Don't know how much postage would be though.

 

[Klaus]

Klaus - Amidon Associates is where I'd check for cores. They deal in small quantities and provide lots of technical information. Palomar might be another.

The local electronics shop had these nice toroidal coils made for just that kind of duty - two windings, one on each side of the form with #14 wire which is good for 15 amps. They were $4 US. I grabbed one. They might still have some. Don't know how much postage would be though.

Thanks, I'll hunt around their websites and see what turns up.
The chokes, 4 of them, are 58mH each and for 12Amps that will be a fair size core to get sufficient turns around it.
Unfortunately I'm writing this from my work computer and there is no way on this Mac to change the drawing format so it will attach. I might redraw it on my home computer and repost here, perhaps some of you more clever fellows have that nifty circuit simulator program and will be able to tell me the attenuation parameters of this filter then.
until later,
Klaus