Abstract: A regulated switched mode power supply comprising a first rectifier adapted to be coupled to a first source of alternating current potential to produce a first source of direct current potential, an oscillator coupled to the first source of direct current potential to produce a second source of alternating current and a second rectifier coupled to the oscillator to produce a second source of direct current potential. The second source of direct current potential being maintained relatively constant with a predetermined range of variations of magnitude of the first alternating current potential by controlling a first pulse width of the second alternating current potential in response to a correction signal. The correction signal is derived by comparing a reference potential and a third direct current potential which is developed across a storage capacitor, the third direct current potential being a function of the first pulse width and the magnitude of the first alternating current potential.