Since all it really is is a heating element, what happens if I use a 240v/50Hz clothes iron with a 110v/60Hz supply?

  • 1
    $\begingroup$ Be careful: if it's a fancy-schmancy iron with tilt sensors, auto-timeout, etc., you might make the low-voltage electronics unhappy. $\endgroup$ Nov 30, 2015 at 12:22
  • $\begingroup$ You might, although if it is fancy-schmancy, it is very likely the low voltage power supply is done right and will do its job both for 110V and for 230V... $\endgroup$
    – 50k4
    Nov 30, 2015 at 15:37

1 Answer 1


In general, anything with a heating element will produce only 1/4 the heat on 1/2 the voltage, since power is proportional to voltage squared.

In other words, you'll probably be disappointed with the results.

  • $\begingroup$ P = IV so why the 1/4 to 1/2 ratio? $\endgroup$ Nov 30, 2015 at 2:14
  • $\begingroup$ With a constant resistance, when you halve the voltage, you also halve the current. $\endgroup$
    – Dave Tweed
    Nov 30, 2015 at 2:21
  • 1
    $\begingroup$ @SteveLorimer - It's P = V^2/R variant in this case, not P = VI $\endgroup$
    – user16
    Nov 30, 2015 at 2:56
  • $\begingroup$ @GlenH7 Both formulae apply. One is more obvious than the other. Also P = I^2 x R. With half voltage you also get half current as I = V/R. Plugging in both I & V figures as approriate gives the same results with all 3 formulae. $\endgroup$ Nov 30, 2015 at 12:43

Your Answer

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

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