| 摘要 |
A rectifier comprising a current transformer configured to receive a bipolar signal. The current transformer is comprised of a primary coil and preferably two secondary coils with opposite polarities. The rectifier also includes a rectifying transistor coupled to one of the secondary coils in the current transformer. Positive current from the first secondary coil causes the transistor to turn on thereby allowing current to flow through the transistor from the input of the rectifier to the output of the rectifier. A pull-down transistor is coupled to a second secondary coil of the current transformer. Positive current from the second secondary coil causes the pull-down transistor to turn on. The pull-down transistor is configured to connect the control terminal of the rectifying transistor to ground, thereby turning the rectifying transistor off, when the pull-down transistor is turned on. The rectifier further comprises a diode coupled to each of the two secondary coils to allow only positive current flow through the secondary coils. The rectifier further comprises a capacitor coupled in parallel with the control terminal of the pull-down transistor which delays switching of the rectifying transistor, thereby permitting zero voltage switching of the rectifying transistor. The rectifier further comprises a hold-down transistor configured to ground the control terminal of the pull-down transistor, thereby holding the pull-down transistor off, when the rectifying transistor is on. Zener diodes are placed in parallel with the control terminals of the pull-down and rectifying transistors to regulate voltage and prevent damage to the transistors.
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