Clamp circuit layout under the transformer?

Posted by: darcioprestes@… on 08/29/2013

I am using an EE16 horizontal bobbin and there's room to place the RCD clamp circuit, including Y capacitor, under the transformer, between the two rows of pins. I mean really under the transformer, not in the opposite side of the PCB.

Is there a problem in routing the board that way? Would it degrade performance or make things dangerous?

PS: LNK626, flyback, 85-265 Vac in, 12 V x 0,5 A out

Comments

Hi,

Would you be possible to share the layout of your board?

Thanks

Please, find it attached!

Hi,

I did take a look at the pic of the layout. I do not know excactly what is the structure of the transformer from the picture, is the core very close to the PCB surface or the core is far from it.

Please pay attention to the creepage / clearance requirement from the primary side and secondary side, since the snubber circuit components are put in between. Also remember that the core of the transformer is conductive, this may create a path to deteriorate the safty from primary to secondary too.

Thanks

The two rows of vertical aligned holes are the primary (left) and secondary (right) connection pins of the transformer. Between them are the componentes of clamp circuit and Y cap.

The transformer has a horizontal bobbin which leaves more space between pins. That's why I've placed them there!

Please just make sure you have enough creepage and clerance between the primary to the secondary since you add the clamping circuit in between.