| 摘要 |
A power supply is disclosed which comprises a ferroresonant circuit, the ferroresonant circuit including a transformer with a core of magnetic material, a primary winding, a secondary winding, and reactive means coupled with at least one of the windings. The transformer also has at least one bias winding. An alternating voltage is applied to the ferroresonant circuit, the alternating voltage having a frequency that is approximately equal to a resonant frequency of the ferroresonant circuit. An output circuit is coupled to the secondary winding. A signal from the output circuit is applied as a feedback signal to the bias winding to control DC flux bias of the core. In an illustrated embodiment, the means for applying an alternating voltage signal to the ferroresonant circuit includes an oscillator for generating alternating voltage control signals, and a switching circuit responsive to an input power source for generating the alternating voltage signals under control of the oscillator. The switching circuit is preferably adapted to provide zero-current switching. The disclosed ferroresonant power supply can operate at relatively high frequencies, for example above 20 KHz and up to about 1 MHz, using standard core materials and without unacceptable losses. Control of the output is obtained by the ferroresonant circuit and without the need for frequency modulation or other circuit complications that are often used with zero-current switching techniques. Also, the disclosed power supply can operate over a wide range of input voltages.
|
