AC Filter

[flintstone mop]

Hello my friends
Is there any source for a known good AC RFI filter for switching power supplies? I see mentioned Corcom. What would fill the bill for a 75W supply? We miss our "under cabinet lights" and the 1 Amp supply I dug up can't cut it for the current draw. The switching supply wrecks Ham radio from 160M to 40M every 30khz with a buzz. I know there will be cool ideas here. And some to get a chuckle or two.
I hope Christmas was a good one for all. Did Santa bring anybody that big B'cast transmitter? Or that nice sounding Raytheon from N3WWL???

Fred

[w3jn]

eBay is your friend.  Here's a lot of eleven 10A filters for ten bux

http://cgi.ebay.com/11-NOS-CDE-APF-10311-EMI-Line-Filter-10A-250VAC_W0QQitemZ180199383129QQihZ008QQcategoryZ7288QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[flintstone mop]

Thanks John
I wonder if those filters will take care of switching power supply noise?? They look a little dated in the ebay pic
Fred

[w3jn]

Similar ones have a common mode atten of about 30 dB at 500 KHz and 45 dB at 30 MHz.  Mount a couple in a project box, put a fuse on it, and cascade them for more attenuation.

[WA1GFZ]

They will need a good ground for best performance

[flintstone mop]

This particular thread is like a cow chewing her cud.
Anyway, I received some very nice AC line filters to play with the "under counter lighting switching power supply"
I'm either doing something outta wack BUT it seems to me that it's a radiated signal on the DC side. The wires leading to the lights make the antenna and you got to have a load, so the P.S. will start. I thought I was getting somewhere running the P.S. unloaded and heard no noise on 160M. I took the P.S. to the load and my test radio and the noise is there no matter how many AC line filters I put in series.
I think there was something in Q street for another switching supply for "driveway lgihts" and auto sprinkler controls to water the grass. The solution may have been running the leads to and from the P.S. through some cores. Does any one remember that as being a solution?

Fred
Fred

[WA1GFZ]

Download the reference put in by W2DU a couple days ago great read. There are plenty of common mode filter ideas in it

[k4kyv]

Wouldn't just tossing the switching power supply and replacing it with a small step-down transformer and feeding the lamps with a.c. do the trick?

We have under-the-cabinet lights in the kitchen that use small fluorescent tubes, and they don't cause any more rfi than CFL light bulbs.

[flintstone mop]

YUP Don,
The mod has been done .A great deal on some big AC 12v transformers from EPay. $9
I just thought I would investigate a conquer...........ha

Fred