Which Young family member pointed out the AC/DC symbol on a sewing-machine adapter?

Margaret Young pointed out the AC/DC symbol on a sewing-machine adapter. Margaret was one of the older Young siblings, while Angus and Malcolm Young later became the band’s best-known members.

The lettering “AC/DC” indicated alternating current and direct current, the two forms of electrical power associated with the device’s power supply. Angus reportedly noticed the label while visiting Margaret, and the unusual, energetic-looking abbreviation appealed to the brothers as a possible band name.

The story is often simplified into the claim that the name came directly from a sewing machine. More precisely, the sewing-machine adapter supplied the visual prompt: the letters were an electrical marking already used on equipment. The band adopted the name in 1973, shortly before its first official performance at Chequers in Sydney.