NV6507 Astable and Monostable Multivibrator Trainer has been designed specifically for the study of Multivibrator in Astable and Monostable mode using IC NE 555. The board is absolutely self contained with in-built supply and pulse generator. The Astable Multivibrator , often called a Free- Running Multivibrator, is frequently used as a simple means of generating square and rectangular wave signal. It has no stable state. The Monostable multivibrator, often called a One-Shot Multivibrator, is useful for generating a single pulse of desired duration in response to an external trigger.