General Accessories Transformers Type ST Transformer type ST 012 Where equipment needs a power supply differing from that of the mains, a transformer can be used to give a suitable alternating voltage. ST 012 Primary circuit Secondary circuit 220 or 380 VAC. 24 VAC, 0.5 A Transformer types ST 024, ST 050, ST 100 ST 024 ST 050 ST 100 Primary circuit Secondary circuit 220 or 380 VAC. ST 024 24 VAC, 1 A ST 050 24 VAC, 2 A ST 100 24 VAC, 4 A Type A B C D E 48 48 64 Ø 3.5 5 4 ST 024 50 ST .