We put forth a range of constant voltage transformers that are highly efficient. In these constant voltage transformers, there are no semi conductors or moving parts that makes them highly reliable. These constant voltage transformers have short term over load capability and higher input voltage control range for loads less than rated load. Precision made, these constant voltage transformers come with very high line rejections capability and excellent input to output isolation characteristics. The other features includes intrinsic current limiting short circuit protection, output voltage corrections within ½ cle (10 m secs ) from no load to full load for specified load and line variation, energy shortage for line loss up to 3(m secs ) at typical loads.