1
\$\begingroup\$

I want to measure which is the effect of the connection of the electrostatic shield (between primary and secondary) to ground (or to neutral) in reducing the interwinding capacitance in my transformer.

How I can simply measure with a multimeter or a LCR the new reduced capacitance between primary and secondary (or the delta interwinding capacitance by using a floating shield or a "grounded" shield)?

\$\endgroup\$
  • \$\begingroup\$ My first thought would be to short both windings and connect one to the + terminal and the other to the - terminal of your LCR meter. \$\endgroup\$ – Hearth May 23 at 17:08
1
\$\begingroup\$

One way that I can think of would be to connect the LCR meter to the shield and to one of the primary or secondary terminals with all other ports on primary and secondary open.

One thing that may get in the way of a capacitance measurement like this is inductance, so try and minimize wire length to the transformer. This would give a rough idea of what the capacitance is.

\$\endgroup\$
  • \$\begingroup\$ Doesn't answer sorry: if the shield is floating or grounded it would return same capacitance. I need to measure the capacitance decrease between primary and secondary when this shield is grounded or connected to the neutral instead being floating \$\endgroup\$ – Gianluca G May 23 at 19:32
  • \$\begingroup\$ Well, you know that the capacitance is not reduced, instead you are just shorting the signal to ground, so the coupling is no longer between windings, but instead from each winding to ground. \$\endgroup\$ – user69795 May 24 at 2:55
0
\$\begingroup\$

You will need to perform this measurement in the presence of a Ground Plane, with the shield(s) tied to the Plane with extremely short paths.

schematic

simulate this circuit – Schematic created using CircuitLab

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.