1 - Constant Voltage, Current, and Power: A Circuit for All Reasons - Derek A. Paice - IEEE Transactionson industrial Electronics and Control Instrumentation , Vol. IECI - 25, NO. 1, FEB. 1978 - pg 55.
2 - The Derivation and Application of Design Equations for Ferroresonant Voltage Regulators and Regulated Rectifiers. - Harry P. Hart and Robert J. Kakalec. - IEEE Transactions on Magnetics, Vol. MAG-7, NO. 1, March 1971.
3 - Standard Handbook for Electrical Eng. - Fink and Beatu - pg. 10-106 to 10-109.
4 - The Geometry of Regulating Transformers - Nathan R. Grossner - IEEE Transactions on Magnetics, Vol. MAG-14, NO. 2, March 1978.
The first one shows how the same circuit may be used as Constant voltage, current or Power.
The second has some useful informations.
MOR_AL