Light dimming system for controlling brightness and rate of change of brightness of lights

Claim 2

A light dimming system including: a dimmer circuit responsive to a voltage signal for controlling the flow of current through a lamp load; and at least one control unit coupled to said dimmer circuit, said control unit comprising: a potentiometer having a tap, the voltage at which determines the level of said voltage signal; a capacitor coupled to said dimmer circuit for storing an electrical charge to thereby develop thereacross a voltage substantially equal to said voltage level; a first conducting means including a first transistor having an emitter and a collector connected in series between the tap of said potentiometer and said capacitor for conducting current from said tap to said capacitor when the voltage at the tap exceeds the voltage across said capacitor; a second conducting means including a second transistor having an emitter and a collector connected in series between said tap of said potentiometer and said capacitor for conducting current from said capacitor to said tap when the voltage across said capacitor exceeds the voltage at said tap; a variable impedance means; and means coupling said variable impedance means to the bases of said first and second transistors and responsive to the impedance of said variable impedance means for controlling the current flow through said first and second conducting means to control the rate of current flow between said tap and said capacitor.

Claim 3

A light dimming system as in claim 1 further including a power supply means for energizing said control unit and wherein said control unit comprises a switching device having a pair of power electrodes connected in series with said power supply means and having a control electrode, means responsive to the activation of said switching device for generating said voltage signal, and first manually operable switch means coupled to the control electrode of said switching device for activating said switching device.

Claim 4

A light dimming system as in claim 2 wherein said control unit further comprises a commutating capacitor, one side of which is coupled to one of the Power electrodes of said switching device, impedance means coupled between the other side of said commutating capacitor and said power supply means, and second manually operable switch means coupled between the other side of said commutating capacitor and the other power electrode of said switching device for disabling said switching device.

Claim 5

A light dimming unit as set forth in claim 3 and including: a plurality of control units connected in parallel with one another to the dimmer circuit each for generating said control signal independently of the other control units; and each of said manually operable switch means is coupled to the switching devices of each of the other control units for disabling all such devices when said second manually operated switch means is operated and for disabling all such devices except the device in the unit operated when said first manually operated switch means in one of said units is operated.

Claim 6

A circuit for controlling the intensity and rate of change of intensity of a lamp load connected to an a.c. source through a dimmer unit of the type having a pair of d.c. control terminals, the magnitude of the voltage at which governs the intensity of the lamp load, which comprises: first and second terminals for connecting to a d.c. source; a controlled switching device; means for connecting said controlled switching device across said source-connecting terminals; means for connecting one control terminal of the dimmer unit to said second source-connecting terminal; means for triggering said controlled switching device; an adjustable potentiometer; means responsive to the triggering of said controlled switching device for impressing a voltage across said potentiometer; first and second complementary transistors having their emitters connected to the tap on said potentiometer; means for connecting the collectors of said first and second complementary transistors to the other control terminal of the dimmer unit to establish opposite current paths through said first and second complementary transistors between said tap of said potentiometer and said dimmer input to increase or decrease the control voltage level in accordance with the potential difference between the initial control voltage level of the dimmer unit and the tap of the potentiometer to equalize the voltage at said tap and said control terminals; a variable resistance; means connecting said variable resistance across said potentiometer; and means coupling said variable resistance to said first and second complementary transistors to control the conductivity of said first and second complementary transistors to vary the rate at which said control voltage level changes.

Claim 7

A circuit for controlling the intensity and rate of change of intensity of a lamp load connected to an a.c. source through a dimmer unit of the type having a pair of d.c. control terminals, the magnitude of the voltage at which governs the intensity of the lamp load, which comprises: first and second terminals for connecting to a d.c. source; a controlled switching device; means for connecting said controlled switching device across said source-connecting terminals; means for connecting one control terminal of the dimmer unit to said second source-connecting terminal; means for triggering said controlled switching device; an adjustable potentiometer; means responsive to the triggering of said controlled switching device for impressing a voltage across said potentiometer; first and second complementary transistors having their emitters connected to the tap on said potentiometer; means for connecting the collectors of said first and second complementary transistors to the other control terminal of the dimmer unit to establish opposite current paths through said first and second complementary transistors between said tap of said potentiometer and said dimmer input to increase or decrease the control voltage level in accordance with the potential difference between the initial control voltage level of the dimmer unit and the tap of the potentiometer to equalize the voltage at said tap and said control terminals; a variable resistance; means connecting said variable resistance across said potentiometer; and means coupling said variable resistance to said first and second complementary transistors to control the conductivity of said first and second complementary transistors to vary the rate at which said control voltage level changes.

Claim 8

A circuit as set forth in claim 5 and including: first manually operable switch means in series with said source terminals for energizing said triggering means to activate said controlled switching device; means responsive to the activation of said switching device for generating said voltage signal; a commutating capacitor connected between said first manually operable switch means and one side of said controlled switching device; and second manually operable switch means for connecting said commutating capacitor across said controlled switching device for disabling said switching device when said second manually operable switch means is operated--.

Claim 9

A circuit as set forth in claim 5 wherein the means for connecting the collectors of said first and second complementary transistors to the other control terminal of the dimmer unit includes first and second diodes arranged in opposite forward current carrying directions in the collector-emitter paths of said first and second transistors, respectively.

Claim 10

A circuit as set forth in claim 7 wherein said conductivity control means includes: third and fourth complementary transistors complementing said first and second complementary transistors, respectively; MEANS connecting the collector-emitter junctions of said third and fourth complementary transistors in series with the bases of said first and second complementary transistors, respectively; and biasing means coupling said variable resistance to said third and fourth complementary transistors to control the conductivity of said third and fourth complementary transistors.