switchers -- input range

Yes. These will describe themselves as 'universal input' and list one wide input range of voltages. Sometimes this is achieved through an automatic switching between ranges (auto-ranging), sometimes through preregulation that may include power factor correction, and in some lower-powered applications simply by operating over the wider range (with the added stress absorbed by adequately rated parts).

For your requirements (none stated), its just a matter of cost and availability. For consumer PCs the most likely parts available will be power-factor corrected supplies in PC form-factor, produced to comply to newer EN61000 harmonic limits. As they are not yet commodities, their pricing reflects the lower volume, rather that the component cost.

For lower-powered projects or those not requiring PC clone form-factor, there are wide-range, pfc corrected or auto-ranging input supplies that are commodities reflecting the requirements of the marketplace listed in didtributor catalogs for your inspection (Power One, Condor and Kaga in the Digikey catalog, as examples).

RL

Err, that's not what I am asking. I am contrasting units that state either of two input voltages vs those that have one WIDE (2-1)range.

What do the 'either' units actually do? I know (as the other responder noted, perhaps a simple full-wave/half wave choice) such is possible

-- my question is what is/was built/sold.

(Or are the "either" units really just wide range ones with a different label?)

Here my query is more theory-based. I know manufacturing costs predominate, and create the bias for the "Any Voltage" design; but I am curious where the piper gets paid when you do so.... (TANSTAAFL.)

I read in sci.electronics.design that David Lesher wrote (in ) about 'switchers -- input range', on Thu, 23 Dec 2004:

AIUI, they have/had a relay which opens its contacts very quickly if subjected to the higher voltage and puts the rectifier into the bridge mode (no voltage-doubling). A 120 V a.c. relay in series with a bridge rectifier with a 120 V zener string across the d.c terminals might be one way to do that.

Your question was explicitly stated, and answered.

Most dual range units work(ed) on the simple single-link-selection of full-wave or full-wave voltage doubler input rectification. Other topologies that switched points in the converter stage were also developed at various times.

The opportunity of using more complicated mechanical switching (dp/dt) or manual plug/link assemblies, allowed the use of linear magnetics and simpler AC air movers, without further design. Some ingenuity was employed getting AC magnetics to move air and power housekeeping based on the single link method, including the use of tapped-winding fan motors being used as autotransformers.

Automatic switchover is typically achieved using a triac in the single link position, or a relay in the complex switch situation. Sanken even manufactured a dedicated smart-power IC with an internal triac for the first technique (from memory the STK8900 and STK8901).

What is/was built/sold? ..... Everything you might think of.

RL

Refreshed memory. Sanken part was STR80145, STR81145 and other variations.

RL