| 摘要 |
A flyback converter high voltage power supply which includes two switches (Q10, Q11) operating in push pull fashion to provide alternate polarity energy pulses to a load (30). A main component of the power supply is a transformer (T10), the primary winding of which is divided into halves (P1, P2). The secondary may also be split into halves (S1, S2), or may be configured without a split so long as the secondary and rectifier combination result in full wave rectification. The first of the two switches (Q10) couples an input voltage (Vin) across the first primary half (P1) to store energy in the magnetic core during a first time interval, and at the end of the first time interval disconnects the first primary half (P1) from the input voltage (Vin). During a second time interval, the energy stored in the magnetic core during the first time interval is delivered to the load (30) via the secondary winding (S1, S2). The second of the two switches (Q11) similarly couples the input voltage (Vin) across the second primary half (P2) to store energy in the magnetic core during a third time interval, and then disconnects the second primary half (P2) from the input voltage (Vin) at the beginning of the fourth time interval. During the fourth time intevral, the energy stored in the magnetic core is again transferred to the load (30) via the secondary. A duty factor modulator is used to control the switching of the first and second switches (Q10, Q11) to vary the length of the time intervals in reponse to variations in the load and input voltage. |
