Constant Voltage Transformer ( CVT ) In our Ferro Resonant type Constant Voltage Transformers - CVT, the AC mains power the input winding, which is widely separated physically from the isolated output winding. The input winding normally runs at very moderate Flux linkage levels.
If a CVT is placed at the output of a square wave inverter (in the UPS), care must be taken to control the frequency of the inverter, since the CVT is sensitive to the frequency of its input supply.
The reason we use a CVT and not a voltage stabilizer for computer applications is that in the voltage stabilizer relays are present and when these relays operate (switch), the output voltage may be interrupted for a short time. Such a transient may not be desirable for computers which may cause the computer to reboot. Also, the CVT provides a clean spike-free output voltage. The voltage regulation possible in a CVT also is good.