Have you seen this circuit before? Pin No. 1 and No. 3 of the transformer are tied and commonly grounded. The transformer does not seem to affect the input/output signal. Does the transformer reduce noise? I can't find it even if I google. Please give me advice if you know it.


lpd6235powershieldedinductor.pdf (coilcraft.com)
This is the datasheet of LPD6235-205.

 

The LPD6235 is a 1:1 coupled inductor. By placing the two coils in series you are effectively creating one inductor. What's interesting is the capacitor banks that are placed in the middle creating a LCL filter. So it would look like a convenient way to design an LCL filter with one inductor component.

 

It looks like some sort of notch filter for common-mode signals.

 

In the application circuits the transformer is part of a switching power supply. That includes a wide realm of variations that are a specialized field of engineering. So examine all of the manufacturers application notes for an adequate explanation.

 

It seems like a bit of an “off label” use of the inductor in question, which was intended for Čuk and SEPIC converters.

 

This is my interpretation of your drawing. I don't fully understand it. AC shouldn't pass through the chokes so I don't know what the cap is doing. And no - I'm not hijacking the thread, I'm not asking for an explanation of how this works. I'm just asking if this is the intended circuit.

 

A common-mode signal on Vin1 and Vin2 would see it as a notch filter, but only if there was sufficient source impedance.
A differential mode signal would see it as a short circuit as the magnetic fields would cancel out, but it does have some significant leakage inductance.
It doesn’t exactly seem that useful.

 

I think the phase of the transformer is wrong in your drawing.

 

It iis still in a switching mode power supply. It is not part of a tuned audio filter. And while a switching power supply looks simple it certainly is not simple to design.Every element of the circuit maters a lot.

 

I think the phase of the transformer is wrong in your drawing.
View attachment 261241
View attachment 261242

=Oh you're right. Thank you

 

I'm sorry. My drawing was wrong. So, This one is correct.

 

Please show us where you found this circuit. What does Vin and Vout come from and go to? There are so many questions!
What is Vin? It appears there is no DC in the circuit. Vin1 to Vin2 must be AC.

 

This is my interpretation of your drawing. I don't fully understand it. AC shouldn't pass through the chokes so I don't know what the cap is doing. And no - I'm not hijacking the thread, I'm not asking for an explanation of how this works. I'm just asking if this is the intended circuit.
View attachment 261221

I'm sorry my drawing was wrong. What about new drawing ??

Please show us where you found this circuit. What does Vin and Vout come from and go to? There are so many questions!
What is Vin? It appears there is no DC in the circuit. Vin1 to Vin2 must be AC.

I'm developing Voltage Multiplier. So, I'm tracking a component that I actually used. Vout1, 2 are input of Voltage Multiplier. As you said, you're right that Vout is AC. And i agree that Vin1,2 also AC.

The Voltage Multipliers I saw on the Internet all controlled the input with a transformer. But the LPD6235 of this component seems very weird. It doesn't affect the input and output. As others say, the noise filter seems to be right. What about your opinion?

 

I am also wondering where the circuit was found, BECAUSE the transformer with that model number is intended for use in a switching mode power converter, and the application intended is not working at mains frequencies.. Worse yet, as a filter, this circuit would be a band-stop high-pass filter, and that makes no sense at all.
Just because a group of symbols can be connected in a drawing does not make it a working circuit able to provide a useful function. This one appears to be taken from an application note and connections added to points that are not that portion of the original intent. Thus analysis of this portion of the circuit will be an exercise in nonsense.

 

I don't see the point of this circuit.

 

I don't see the point of this circuit.

Agree. We are not allowed to see the entire circuit. As little as we know it does nothing.

 

Found this. Definitely drawn wrong. Hover over the LPD6235-205MR_ and the phasing of the transformer shows up. The data sheet has a lot of information on the part.

 

Someplace there must be an application note, and that will be found to relate to a switching power supply application, at least that is the portion of the circuit that I saw in the data sheet. The other major application for a device with this symbol is as an input line choke, with two coupled but insulated windings in series with both sides of the AC mains input. But every one of the properties needed for that application are different from a the power inductor in a switcher power supply.

This thread is beginning to smell like some troll bait! At least that is what I smell.

 

Someplace there must be an application note, and that will be found to relate to a switching power supply application, at least that is the portion of the circuit that I saw in the data sheet. The other major application for a device with this symbol is as an input line choke, with two coupled but insulated windings in series with both sides of the AC mains input. But every one of the properties needed for that application are different from a the power inductor in a switcher power supply.

This thread is beginning to smell like some troll bait! At least that is what I smell.

It wouldn’t make a very good common mode choke - common mode chokes are not made with gapped ferrite, they are designed to achieve as much inductance as possible from the core.

 

It wouldn’t make a very good common mode choke - common mode chokes are not made with gapped ferrite, they are designed to achieve as much inductance as possible from the core.

Don't confuse him with real knowledge.