These operating instructions are for the Universal Isolated Stimulator Output (UISO) type 263 (catalog code 73-0504 and 73-2696). The UISO represent an isolated high-power stimulator output stage for use in physiological and pharmacological research. The unit incorporates its own power supply; special measures are used to ensure that any interference voltage or current introduced into the output stage through capacitive coupling is very low. The required stimulation signal (square-wave pulse) can be provided by any stimulator. A built-in microcomputer monitors the stimulation signal input and suppresses stimulus patterns which could cause the unit to overheat. DC Stimuli (=DC voltage) can not be produced.