Switch Mode or Transformer Type UPS?

transformer type ups is best of home use....

switch mode power supply type is mostly used for fast response but it is equipped with harmonics suppressing circuitry which make it more costly as compared with simple transformer.

If you are using it for simple everyday home items...go with the cheaper and smaller (more efficient) SMPS.

If you are worried about excessive noise for sensitive electronic processing...such as a home studio (audio/analog)...go for the "transformer type". With a proper (power) system in place this will give the best performance (read...quiet and clean power).

The major components of UPS are Battery charger, Battery and Inverter. The battery charger uses either half wave or full wave rectifier technology. Neither the 'Switch Mode' nor the 'Transformer Type' applies to the charger. Since the charger is connected to your electric system, the injection of harmonic doesn't change whether you select 'Switch Mode' or 'Transformer Type'.

'Switch Mode' and 'Transformer Type' are the technologies used in inverter to convert DC to AC. 'Switch Mode' could be either PWM (Pulse Width Modulation) or Step Wave, but use of PWM is more common than Step Wave. On the other hand, the 'Transformer Type' uses the ferroresonant transformer for converting the square wave to sine wave. See http://cr4.globalspec.com/comment/538790 for more detail. In 'Transformer Type' inverter, switch mode is partly used to convert the DC voltage to positive and negative square wave.

The 'Transformer Type' is good when constant output voltage is required. Ferroresonant transformer maintains constant output with the variation of the DC input voltage over a range. See http://www.dieboldpwr.com/pwmferro.html for more pros and cons.

- MS

"'Switch Mode' and 'Transformer Type' are the technologies used in inverter to convert DC to AC. '"

Not really...

Switch mode most commonly refers to the method of rectification of the incoming AC signal. The chop frequency produces artifacts and induces harmonics on the incoming power, as well as negatively affecting power factor.

Wikipedia explains this rather well, as well as the IEEE color book series in several volumes.

transformer based systems are less suceptible to lightening transients.

Switch-mode devices (at any appreciable power) DO use transformers. "Switch mode" means a transistor switches a transformer primary on and off.

Question is a little vague.