* AUD/USD hits 0.7768 after extending south from 0.7815 (early Europe high)
* Drop to 0.7768 influenced by 3% copper price fall
* European equity losses are also weighing on risk-sensitive AUD
* 0.7753 (Asia low) and 0.7737 (Tuesday's low) are AUD/USD support points
* Tuesday's low was plumbed after dovish RBA. Fed's Powell speaks at 1705GMT
(Robert Howard is a Reuters market analyst. The views expressed are his own) ((robert.howard@thomsonreuters.com))