Hello. I've been looking at common mode chokes and there was something I was wondering. Their frequency response is much much better than a regular inductor. So could you use a common mode choke as a DC-pass on a single-line by running the line through both channels of the choke?
Or is there a reason I've never seen this.
The neutral in my circuit is moving up and down with a virtual ground to the BLDC caused by the switching of my motor driver. I already have chokes that supress the common mode noise at the amplifier inputs (which is basically the only path that common mode noise between either power rail and neutral can get in. But there is still basically just a direct copper connection from this floating neutral right into the power supply neutral so common mode signals can travel straight through.
I can't seem to find a 3-line choke that will do. TO demonstrate the problem is my Example schematic (with two chokes for no reason just to make things more clear). THere is a straight path along neutral for common mode currents to travel even though most of the other paths have been blocked. Of course, there is the common mode path between +5V and -5V, but that has been blocked by the front-end amplifier chokes.
The two remaining schematics try to show how the chokes on the amplifiers block most common mode noise that can get through to the power supply, except for the one path through the neutral which I want to block by using the choke on a single line.
Or is there a reason I've never seen this.
The neutral in my circuit is moving up and down with a virtual ground to the BLDC caused by the switching of my motor driver. I already have chokes that supress the common mode noise at the amplifier inputs (which is basically the only path that common mode noise between either power rail and neutral can get in. But there is still basically just a direct copper connection from this floating neutral right into the power supply neutral so common mode signals can travel straight through.
I can't seem to find a 3-line choke that will do. TO demonstrate the problem is my Example schematic (with two chokes for no reason just to make things more clear). THere is a straight path along neutral for common mode currents to travel even though most of the other paths have been blocked. Of course, there is the common mode path between +5V and -5V, but that has been blocked by the front-end amplifier chokes.
The two remaining schematics try to show how the chokes on the amplifiers block most common mode noise that can get through to the power supply, except for the one path through the neutral which I want to block by using the choke on a single line.
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