The Kepco Mode! BOP 500M and BOP Ί000Μ are high voltage power sources, which combine the capabilities of fast programmable power supplies with a Class A output stage, which can respond bidirectionally from zero. The "BOP" can be operated in a "Voltage Stabilizing" or "Current Stabilizing” operating mode (selectable by a front panel switch}. The 80P incorporates two separate control channels, for local (front panel) or remote control of the output current and the output voltage, in addition, bounding currents for bipolar voltage and current limiting are provided which may be adjusted manually (by front panel controls) or can be remotely programmed. Ail control and bounding channels are connected to the bipolar (Class A) output stage via an "EXCLUSIVE-OR" gate, so that only one circuit is in control of the BOP output at any one time. Some applications are listed befow: A) VOLTAGE MODE OPERATION. (Current limiting either front panel adjusted or remotely programmed using the current limiting channel). 1) High speed, bipolar d-c voltage source (remote or locally controlled output). 2) Scaling or summing amplifier with or without d-c bias. B) CURRENT MODE OPERATION (Voltage limiting either front panel adjusted or remotely programmed using the voltage limiting channel). 1) High speed, bipolar d-c current source (remotely or locally controlled output). 2) Amplification of a-c currents, with or without d-c biasing.