RE: not sure what you mean by outside of the chokes

Posted by rick_m (A) on September 21, 2008 at 20:20:34

In Reply to: not sure what you mean by outside of the chokes posted by Slider on September 21, 2008 at 10:18:52:

Sorry for the confusion. I was just thinking that it should be desirable to have a choke isolated common to reduce the power system as a source of crosstalk noise.

Actually I'm now more interested in the differential output capacitors. I can see that they reduce rail to rail noise, but it seems to me that you end up with a rather high supply impedance when trying to drive an unbalanced load. Say you want to deliver some positive current to a load, it looks to me that the energy is going to end up coming from the input capacitor, C5 through the choke and that the output capacitors won't help very much as they go through another choke and have half the value the effective value and ESR that they would have if they were connected to ground. Why do you connect them differentially? For that matter, why use half-wave rectification?

I'm probably missing the point (old age and dry rot?). Are you trying to increase the dynamic impedance to allow more effective local bypassing or something of that nature?

Rick

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Follow Ups Full Thread

Topic - I need to learn the ABCs of chokes & caps in power supplies - Christopher Witmer 23:57:35 09/17/08 (19)

Power supply noise issues. - Al Sekela 11:11:15 09/18/08 (0)

A big advantage for me was getting rid of electrolytic caps - Slider 09:00:23 09/18/08 (8)

RE: A big advantage for me was getting rid of electrolytic caps - Tarquineous 00:06:54 09/21/08 (7)

RE: A big advantage for me was getting rid of electrolytic caps - Slider 08:46:30 09/21/08 (6)

RE: A big advantage for me was getting rid of electrolytic caps - rick_m 09:45:12 09/21/08 (5)

not sure what you mean by outside of the chokes - Slider 10:18:52 09/21/08 (4)

RE: not sure what you mean by outside of the chokes - rick_m 20:20:34 09/21/08 (3)

It is a full wave rectifier - Slider 21:36:50 09/21/08 (2)

RE: It is a full wave rectifier - rick_m 08:16:16 09/22/08 (1)

shunt regulators - Slider 08:36:34 09/22/08 (0)

Take an electronics class - Tweekeng 07:40:38 09/18/08 (0)

I'll gave you some quick info - Russ57 05:10:19 09/18/08 (6)

Is there merit in using both together, or does it "depend"? - Christopher Witmer 06:56:36 09/18/08 (5)

In general, you always would - Russ57 08:35:48 09/18/08 (4)

Speed of chokes versus caps - Christopher Witmer 15:45:57 09/18/08 (3)

"Speed" of chokes and caps - Al Sekela 10:18:49 09/19/08 (1)

We could write a book:) - Russ57 11:57:39 09/19/08 (0)

This is where you have to model - Russ57 07:12:13 09/19/08 (0)

Why not search.... - Uncle Mike 03:56:02 09/18/08 (0)

Follow Ups

RE: not sure what you mean by outside of the chokes - rick_m 20:20:34 09/21/08 (3)

It is a full wave rectifier - Slider 21:36:50 09/21/08 (2)

RE: It is a full wave rectifier - rick_m 08:16:16 09/22/08 (1)

shunt regulators - Slider 08:36:34 09/22/08 (0)

RE: not sure what you mean by outside of the chokes

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