Current control circuit for a plurality of loads

Claim 2

An electronic control circuit for controlling the load current flowing through a plurality of loaDs, comprising: a plurality of current amplifying means, each supplying a load current to a corresponding one of said plurality of loads; current detecting means coupled to the outputs of the loads for detecting a magnitude of a current flowing through said plurality of loads; 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 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; and a plurality of switching means coupled between said amplifying means and the respective current amplifying means for selectively controlling the input to said current amplifying means, whereby said plurality of loads 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.

Claim 3

An electronic control circuit for controlling the load current flowing through a plurality of loads, comprising a plurality of current amplifying transistors each 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 plurality of loads 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 and 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; and 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 loads are selectively energized by a current, the instantaneous magnitude of which is proportional to said reference signal at a current rate regardless of the differences in the gains of said current amplifying transistors.

Claim 4

An electronic control circuit for controlling the load current flowing through a plurality of loads, comprising a plurality of current amplifying transistors each 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 plurality of loads 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 and 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; and 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 loads are selectively energized by a current, the instantaneous magnitude of which is proportional to said reference signal at a current rate regardless of the differences in the gains of said current amplifying transistors.

Claim 5

An electronic control circuit as claimed in claim 2 wherein said detecting means comprises a resistor.

Claim 6

An electronic control circuit as claimed in claim 2 wherein said detecting means comprises a first resistor coupled between a terminal of said power supply and a common point of said plurality of parallel connected series connections, a second resistor and a transistor having a base, an emitter and a collector, said base being connected to said common point, said emitter being connected to said terminal of said power supply through said second resistor and said collector being the output terminal of said current detecting means.