Current control circuit for a plurality of loads

Claim 2

A direct current motor having a magnetic rotor and an electronic control circuit for controlling the load current flowing through a plurality of stator windings, comprising: a plurality of current amplifying means to operate in a nonsaturating mode and being coupled to respective stator windings, each supplying a load current to a corresponding one of said stator windings; current detecting means coupled to the outputs of the stator windings for detecting a magnitude of a current; reference signal means for generating a reference signal; comparator means coupled to said current detecting means and said reference signal means for providing an output of said current detecting means and said reference signal; amplifying means coupled to said comparator means for amplifying said output signal of said comparator means; a plurality of switching means coupled between said amplifying means and the respective current amplifying means for selectively controlling the inputs to said current amplifying means, whereby said plurality of stator windings are selectively energized by a current, the instantaneous magnitude of which is proportional to said reference signal at a constant rate, regardless of the differences in the gains of said current amplifying means; and position detecting means producing a set of position signals to indicate the rotary position of said rotor relative to said stator windings, said position detecting means being coupled to said plurality of switching means so that one of said plurality of switching means is selectively switched on.

Claim 3

A direct current motor having a magnetic rotor and an electronic control circuit for controlling the load current flowing through a plurality of stator windings, comprising: a plurality of current amplifying transistors for operation in a non-saturating mode and having a base, an emitter and a collector, the emitter-collector path of each said current amplifying transistors being connected to a respective one of said stator windings in a series connection, the plurality of said series connections being connected in parallel to each other; a power source; current detecting means connected between said power source and said parallel connected series connections and having an output terminal; reference signal means generating a reference signal; comparator means coupled to said current detecting means to said reference signal means for providing an output signal equal to the difference between the output of said current detecting means and said reference signal; amplifying means coupled to said comparator means for amplifying said output signal of said comparator means; a plurality of switching means coupled between said amplifying means and the bases of said current amplifying transistors for selectively controlling said bases of said plurality of current amplifying transistors, whereby said plurality of stator windings are selectively enErgized by a current, the instantaneous magnitude of which is proportional to said reference signal at a constant rate, regardless of the differences in the gains of said current amplifying transistors; and position detecting means producing a set of position signals to indicate the rotary position of said rotor relative to said stator windings, said position detecting means being coupled to said plurality of switching means so that one of said plurality of switching means is selectively switched on.

Claim 4

A direct current motor having a magnetic rotor and an electronic control circuit for controlling the load current flowing through a plurality of stator windings, comprising: a plurality of current amplifying transistors for operation in a non-saturating mode and having a base, an emitter and a collector, the emitter-collector path of each said current amplifying transistors being connected to a respective one of said stator windings in a series connection, the plurality of said series connections being connected in parallel to each other; a power source; current detecting means connected between said power source and said parallel connected series connections and having an output terminal; reference signal means generating a reference signal; comparator means coupled to said current detecting means to said reference signal means for providing an output signal equal to the difference between the output of said current detecting means and said reference signal; amplifying means coupled to said comparator means for amplifying said output signal of said comparator means; a plurality of switching means coupled between said amplifying means and the bases of said current amplifying transistors for selectively controlling said bases of said plurality of current amplifying transistors, whereby said plurality of stator windings are selectively enErgized by a current, the instantaneous magnitude of which is proportional to said reference signal at a constant rate, regardless of the differences in the gains of said current amplifying transistors; and position detecting means producing a set of position signals to indicate the rotary position of said rotor relative to said stator windings, said position detecting means being coupled to said plurality of switching means so that one of said plurality of switching means is selectively switched on.