I built me a power supply using a LM350, but when I have amplifer hooked up to it, I have RF in supply. What can i do do reduce or alleviate this? I did a circuit as given on datasheet. But could not figure out anything for RF bypassing. Any help would be great.
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RFI in power supply
- Thread starter Crusher
- Start date
Have you tried adding RF bypassing to pin #1 the adj pin? Something between 0.01 and 1 uF to ground should do.
Yes, it is recommended to use a .1/104 for input anyways. I think I have a 25uf as well. Guess I may have to experiment a bit more. I do not have an LC network on the output. This power supply is capable of 100+ Amps continous. So making an inductor that will handle that kinda dc current would be difficult at best. Yes?
Yes? Definitely YES! That'd be one big choke. You might try just the caps though, some times works well enough. Haven't seen a choke that big in years, no idea if anyone is still selling them. Good luck.
- 'Doc
Or, see what others have used for output filtering. If it work, it works. Who cares where the idea came from?
- 'Doc
Or, see what others have used for output filtering. If it work, it works. Who cares where the idea came from?
Do you mean you don't have ANY filtering on the output of the PS? Not even some good-sized electrolytic capacitors?
I hope you didn't try using it without at least that much filtering; you wouldn't be able to tell RF in the power supply from the raw, unfiltered 120 Hz DC.
I hope you didn't try using it without at least that much filtering; you wouldn't be able to tell RF in the power supply from the raw, unfiltered 120 Hz DC.
It has filtering, about 100,000uf. The regulator circuit is used in a circuit that combines 2 12V batteries. There shouldn't be much in the way of frequency strictly combining 2 batteries anyways. I have tested it and everything works fine other than I noticed that the light on the switch gets brighter as amp hooked to power supply is modulated. Everything else works fine. I added a bit more ferrite and a few more bypassing capacitors. Will have to test it later today and see what happens.
Removed 2 capacitors that were installed in the regulator circuit and added 1 cap. of a different value and seems to work fine now.
Oh I definitely was last night shooting DX in the mobile. What the regulator circuit was for was for a motor maul of the 200A version.
Thank you everyone
73's
Crusher
Thank you everyone
73's
Crusher