Improved asymmetrical half-bridge converter using a tapped output inductor filter

The asymmetrical half-bridge converter (AHBC) has the attractive features of zero voltage switching (ZVS) and voltage clamping. However, the converter is not suitable for wide input voltage range applications since it has the problem of a 50% maximum allowable duty cycle. A new AHBC topology with a tapped output inductor filter is proposed that not only extends the allowable operating duty cycle but also makes the ZVS condition less stringent. The principle of operation is explained and analysed. Experimental results obtained from a 24V/3 A prototype are presented, which illustrate converter function and verify the analytical results.