| 摘要 |
<p>In a zero voltage switching, forward converter, switch mode power supply, a primary winding (T1W1) of a chopper transformer (T1) is coupled to a chopper transistor (Q1). A current transformer (T2) has a primary winding (T2W1) coupled in series with the chopper transistor. The secondary winding (T2W2) of the current transformer is coupled to the base of the chopper transistor. The current transformer couples the chopper transistor collector current to the base to provide proportional drive. After the chopper transistor is turned off, the current transformer couples a resonant voltage (VQ1) developed at the collector of the chopper transistor to the base for controlling the instant when the chopper transistor is turned on in a manner to provide for zero voltage switching.</p> |
