Active Clamp Flyback Controller for Zero Voltage Switching

The patent introduces a transmitting circuit as an intermediary component that bridges the primary and secondary sides. This circuit transmits load current information from the secondary side to the primary side, enabling the controller to perform zero voltage switching control without directly detecting secondary-side current. The transmitting circuit acts as a mediator that conveys necessary information across the isolation barrier, resolving the contradiction by providing control capability while maintaining circuit simplicity.

The patent creates a copy of the load current information by detecting it on the secondary side and transmitting it to the primary side. Instead of requiring complex direct detection circuits on the primary side, the system copies the essential current information across the transformer isolation barrier. This copying approach enables accurate control while using simpler, more cost-effective circuit implementation.

The transmitting circuit serves as a cost-effective intermediary that enables control functionality without requiring expensive direct secondary-side current detection circuits on the primary side. By using this intermediary approach, the patent achieves zero voltage switching control at a lower manufacturing cost compared to implementing full secondary-side detection hardware.

The patent employs a simple transmitting circuit that uses minimal components (resistors, capacitors, and transistors) to achieve the control function. This approach replaces expensive complex detection circuits with a cheaper, simpler alternative that performs the necessary information transmission task effectively.

The transmitting circuit acts as an intermediary that transfers load information without requiring high-value detection resistors that would generate significant power loss. By using this intermediate transmission approach, the system obtains necessary load information while minimizing energy dissipation in detection components.

The patent replaces direct electrical current measurement (which would require power-consuming resistors) with an indirect information transmission method. Instead of mechanically measuring current on the primary side, the system uses electrical signal transmission from the secondary side to convey load information, thereby substituting a power-lossy measurement approach with a more efficient signal transmission approach.