swˈɪtʃtmˈoʊd pˈaʊɚ səplˈaɪz hæv bɪkˌʌm wˈaɪdspɹɛd ɪnðɪ ˈɜːli twˈɛntifˈɜːst sˈɛntʃɚɹi; ðeɪ ɑːɹ smˈɔːlɚ ænd lˈaɪɾɚ ðɐn ðə wˈʌnsjˌuːnɪvˈɜːsəl tɹænsfˈoːɹmɚ kənvˈɜːɾɚz, ænd ɑːɹ ˈɔfən dɪzˈaɪnd tə wˈɜːk fɹʌm ˌeɪsˈiː mˈeɪnz æɾ ˌɛni vˈoʊltɪdʒ bᵻtwˌiːn wˈʌnhˈʌndɹɪd ænd tˈuːhˈʌndɹɪd fˈɪfti vˈiː. ɐdˈɪʃənəli, bɪkˈʌz ðeɪ ɑːɹ tˈɪpɪkli ɹˈɛktᵻfˌaɪd tʊ ˈɑːpɚɹˌeɪt æɾə dˌiːsˈiː vˈoʊltɪdʒ, ðeɪ ɑːɹ mˈɪnɪməli ɐfˈɛktᵻd baɪ ðə fɹˈiːkwənsi ʌvðə mˈeɪnz fˈɪfti vˌiːˈɛs sˈɪksti ˌeɪtʃzˈiː.
Switched-mode power supplies have become widespread in the early twenty-first century; they are smaller and lighter than the once-universal transformer converters, and are often designed to work from AC mains at any voltage between 100 and 250 V. Additionally, because they are typically rectified to operate at a DC voltage, they are minimally affected by the frequency of the mains (50 vs 60 Hz).