* 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))