Subclass 3/0234: Circuits for generating electric pulses; Monostable, bistable or multistable circuits (H03K 4/00 takes precedence; for digital computers G06F 1/025) Generators characterised by the type of circuit or by the means used for producing pulses (H03K 3/64-H03K 3/84 take precedence) by the use of differential amplifiers or comparators, with internal or external positive feedback Multistable circuits