The 2510/2520 Series Variable Transformers represent a compact
high current variable transformer design. The 2510, 120
volt unit is rated at 25 amperes for constant current loads; while
the 2520, 240 volt unit is rated at 10 amperes for constant current
loads. Constant impedance ratings are listed in the specifications.
They can be operated at frequencies between 50 and
2000 Hertz with derating at higher than rated frequency