A transformer's A.C. current rating needs to be recalculated from the D.C. load current:
http://www.hammondmfg.com/pdf/5c007.pdf
According to this, for a ‘
FULL WAVE BRIDGE Capacitor Input Load':
- I D.C. = 0.62 X Sec. I A.C
A 15 V 20 VA transformer is rated 1.33 amp a.c. This corresponds to about 0.83 amp with a full wave bridge and capacitor load.
David