| 摘要 |
<p>A limiting circuit (12) for an active clamp comprising a reset switch (8) and reset capacitor (9), for use in particular with a forward converter is discIosed. The Iimiting circuit (12) provides for limiting the voltage across the reset switch (8) by disconnecting the reset switch (8) from the reset capacitor (9) during a part of the switching cycle when the voltage across reset capacitor (9) is too negative.
The reset switch (8) may be grounded by the limiting circuit or connected to another reference voItage. In another embodiment the reset switch (8) is capacitively coupled to ground and thereby enables detection of fault conditions. Further, the voltage across a switch (14) of limiting circuit (12) may be constrained by the breakdown value of a Zener diode (17).</p> |
