by the use of galvano-magnetic devices, e.g. Hall effect devices

Full Title

Circuits for generating electric pulses; Monostable, bistable or multistable circuits (H03K4/00 takes precedence; for digital function generators in computers G06F1/02) > Generators characterised by the type of circuit or by the means used for producing pulses (H03K3/64 - H03K3/84 take precedence) > by the use of galvano-magnetic devices, e.g. Hall effect devices