Guru
Joined: 31/12/2012
Location: New ZealandPosts: 2526
| Posted: 08:19am 30 May 2024 |
unlikely that they don't use a SMPS. to achieve operation at both 110v and 230v without any series/parallel switch at the primary requires you to oversize a normal 50/60Hz transformer such that it can:
(a) operate at 230v without overheating,
(b) at 110v still deliver sufficient voltage and current at the secondary.
the end result is a transformer that needs to be several times bigger than would otherwise be needed. if followed by a linear regulator, that also needs to be oversized to handle the increased rectified voltage when there is 230v on the primary.
the only device i've come across with such an arrangement is the Fluke 45 bench meter, that can handle something like 90v to 264v AC. Fluke use a buck converter after the mains transformer to cater to the wide (10-30v DC) rectified voltage range.
for a discussion about replacing the transformer in a Fluke 45 see:
https://www.eevblog.com/forum/repair/fluke-45-transfomer-foobar/msg5314255/#msg5314255
cheers,
rob :-)
addendum: from the datasheet and manufacturer's website, "The DTKom Series amplifiers incorporate a built in switched 110-230V AC power supply and are characterized by their exceptionally low power consumption for a long and trouble-free operating life", and, "Includes a high-performance low-power consumption switch-mode power supply".
Edited 2024-05-30 18:41 by robert.rozee