The 4500 series is a power amplifier which has frequency range of from DC to 20kHz . It is available for a constant current output and a remote sensing. It is appropriate for power environments testing by none-sinusoidal waveform like instantaneous break of half wave.
 
 
Wide rage : DC to 20kHz
High output voltage : ± 200V
Four modes of DC (CC/CV) and AC (CV/CC)
Output voltage can be boosted up by serial connection.
The 4521 Power Booster combined with the 4520A enable power expansion.