0
\$\begingroup\$

I have generated a transformer assembly project online for my flyback transformer.

The Diagram:

Transformer Electrical Diagram

The Winding instructions:

enter image description here

How do I connect the Primary First coil and the Primary second coil to obtain the correct electrical diagram?

\$\endgroup\$
1
\$\begingroup\$

How do I connect the Primary First coil and the Primary second coil to obtain the correct electrical diagram?

Look at the bobbin below and the pins I've marked in red, green and purple: -

enter image description here

Option 1

  • Connect Primary First to red pins and
  • Primary Second to purple pins
  • Join pins 2 and 4 on the PCB.

Option 2

  • Connect Primary First to pin 1 and pin 3 (green)
  • Connect Primary Second to (same) green pin and pin 5 (purple)

In these options be sure that the direction of winding on the bobbin remains consistent on all windings.

You can of course use pins 6 to 10 as an alternative to pins 1 to 5 for the primary windings.

  • For the secondary winding, use pins 6 and 7 or 9 and 10.

  • For the tertiary (auxiliary) windings use pins 9 and 10 or 6 and 7 i.e. the spare pins left after choosing the secondary pins. Leave the middle pin free to promote extra clearance.

As the primary wires come from the bobbin to the pins it might be good practice to sleeve them to prevent criss-crossing primary and secondary wires rubbing against each other.

You might also consider a 90% coverage in copper tape around the finished windings that can be grounded on (say) pin 8. If ground isn't used as an electrical connection you can usefully tie the screen to the negative supply of the bridge rectifier as a means of shunting away some noise.

| improve this answer | |
\$\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.