1
\$\begingroup\$

I am simulating a dc battery charger. The circuit contains a step down transformer enter image description here

I will need to lower the tension from 311 V (Vp) (or 220 RMS) to 15 V (Vp). One possible option for the turn ratio would be nprimary=311, nsecondary=15. But I highly doubt I could find practical transformers with this turn ratio. So is there any table/reference where I can find standard (or at least common) values of transformers turn ratios?

\$\endgroup\$
3
  • \$\begingroup\$ When you look in a list / catalog of transformers, they are typically sorted by ratio, not by number of windings. \$\endgroup\$
    – Marcus Müller
    Nov 11, 2020 at 18:17
  • 1
    \$\begingroup\$ ... and they will be rated in primary and secondary RMS voltage - not peak voltage. Standard secondary voltages will include 6, 9, 12, 15, 18 and 24 V rms with 115 / 230 nominal primaries. \$\endgroup\$
    – Transistor
    Nov 11, 2020 at 18:22
  • \$\begingroup\$ The number of turns does more than apply a simple ratio - it also indicates how much power the transformer can move from primary to secondary. Consider your 311:15 transformer idea.... If you used 21 turns on the primary and only 1 on the secondary, you'd get (about) the same ratio. But you already know that ain't gonna work! Transformer design is a complicated subject, you're best off just buying one off-the-shelf that delivers the voltage you need and (at least) the current you need. BTW, you do NOT need to hit 15V exactly in your circuit - You have a regulator. 16V would be ok too. \$\endgroup\$
    – Kyle B
    Nov 11, 2020 at 22:54

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Browse other questions tagged or ask your own question.