Solid state electronic dimmer

Claim 2

Dimmer apparatus for variably controlling the current from an AC source supplied to a lamp load comprising terminals for coupling said apparatus between and AC power source and the lamp load, a source of control signal voltage, solid state circuit means coupled to said control signal voltage for adjustably reducing the AC source voltage at the lamp load terminal, means in said solid state circuit for adjustably changing the transfer characteristic between the adjustable control signal value and the AC voltage applied to the lamp load.

Claim 3

The apparatus as claimed in claim 1 which further comprises means for substantially eliminating radio interference.

Claim 4

The apparatus as claimed in claim 2 in which means for adjustably changing the transfer characteristic comprises a negative feed back control circuit.

Claim 5

Apparatus for variably controlling the current from an AC source supplied to an incandescent lamp load comprising a pair of terminals for connecting said apparatus to said source, a pair of gate controlled rectifiers, each of said gate controlled rectifiers respectively comprising anode, cathode, and gate electrodes, connected in their anode to cathode paths in inverse parallel relationship across said terminals, a unijunction transistor relaxation oscillator comprising a transistor having emitter and first and second base electrodes, said emitter being connected to a variable unidirectional control signal source, means for deriving a unidirectional voltage from said AC source and for applying said last named signal as an operating biasing potential to said transistor, means for applying said control signal to said emitter to produce a pulse train output from said transistor in which each of the pulses comprising said train respectively occur during discrete half cycles of said AC source output, the times of occurrence of said pulses within said half cycles being determined by the magnitude of said control signal, means for applying said pulses to said gate electrodes to render said rectifiers alternately conductive in successively occurring half cycles substantially simultaneously with the occurrence of said pulses, means for applying the outputs of said gate controlled rectifiers to said load, means connected across said load for deriving a unidirectional signal to produce an adjustable transfer characteristic for said load for differing lighting conditions, and means for adjusting said bias for the emitter of said transistor for providing a voltage at the lamp load for a zero value of said control signal.

Claim 6

Apparatus for variably controlling the current from an AC source supplied to an incandescent lamp load comprising a pair of terminals for connecting said apparatus to said source, a pair of gate controlled rectifiers, each of said gate controlled rectifiers respectively comprising anode, cathode, and gate electrodes, connected in their anode to cathode paths in inverse parallel relationship across said terminals, a unijunction transistor relaxation oscillator comprising a transistor having emitter and first and second base electrodes, said emitter being connected to a variable unidirectional control signal source, means for deriving a unidirectional voltage from said AC source and for applying said last named signal as an operating biasing potential to said transistor, means for applying said control signal to said emitter to produce a pulse train output from said transistor in which each of the pulses comprising said train respectively occur during discrete half cycles of said AC source output, the times of occurrence of said pulses within said half cycles being determined by the magnitude of said control signal, means for applying said pulses to said gate electrodes to render said rectifiers alternately conductive in successively occurring half cycles substantially simultaneously with the occurrence of said pulses, means for applying the outputs of said gate controlled rectifiers to said load, means connected across said load for deriving a unidirectional signal to produce an adjustable transfer characteristic for said load for differing lighting conditions, and means for adjusting said bias for the emitter of said transistor for providing a voltage at the lamp load for a zero value of said control signal.

Claim 7

The apparatus as claimed in claim 4 in which said means for applying said control signal to said emitter of said transistor comprises a second transistor to which said control signal is applied, the output of said second transistor being applied to said emitter, and a third transistor to which said unidirectional signal is applied having its output also coupled to said emitter.

Claim 8

The apparatus as claimed in claim 5 in which said coupling of the said unidirectional signal to said third transistor comprises a serially coupled Zener diode and a variable resistor.

Claim 9

Apparatus for variably controlling the current from an AC source supplied to an incandescent lamp load comprising a pair of terminals for connecting said apparatus to said source, a pair of gate controlled rectifiers, each of said gate controlled rectifiers respectively comprising anode, cathode, and gate electrodes connected in their anode to cathode paths in inverse parallel relationship across said terminals, a unijunction transistor relaxation oscillator comprising a first transistor having emitter and first and second base electrodes, said emitter being connected to a variable unidireCtional control signal, said emitter connection comprising a second transistor to which said control signal is applied with the output of said second transistor being applied to said emitter, means for deriving a unidirectional voltage from said AC source and for applying it as an operating biasing voltage to said first transistor, a third transistor having its output also coupled to said emitter, means coupling said unidirectional biasing voltage to said third transistor comprising a Zener diode and a variable resistor, said control signal being adjustable to produce a pulse train output from said first transistor in which each of the pulses comprising said train respectively occur during discrete half cycles of said AC source output, the times of occurrence of said pulses within said half cycles being determined by the magnitude of said control signal, means for applying said pulses to said gate electrodes to render said rectifiers alternately conductive in successively occurring half cycles substantially simultaneously with the occurrence of said pulses, means for applying the outputs of said gate controlled rectifiers to said load, and means connected across said load for deriving a unidirectional signal to produce an adjustable transfer characteristic for said load for differing lighting conditions.

Claim 10

Apparatus for variably controlling the current from an AC source supplied to an incandescent lamp load comprising a pair of terminals for connecting said apparatus to said source, a pair of gate controlled rectifiers, each of said gate controlled rectifiers respectively comprising anode, cathode, and gate electrodes connected in their anode to cathode paths in inverse parallel relationship across said terminals, a unijunction transistor relaxation oscillator comprising a first transistor having emitter and first and second base electrodes, said emitter being connected to a variable unidireCtional control signal, said emitter connection comprising a second transistor to which said control signal is applied with the output of said second transistor being applied to said emitter, means for deriving a unidirectional voltage from said AC source and for applying it as an operating biasing voltage to said first transistor, a third transistor having its output also coupled to said emitter, means coupling said unidirectional biasing voltage to said third transistor comprising a Zener diode and a variable resistor, said control signal being adjustable to produce a pulse train output from said first transistor in which each of the pulses comprising said train respectively occur during discrete half cycles of said AC source output, the times of occurrence of said pulses within said half cycles being determined by the magnitude of said control signal, means for applying said pulses to said gate electrodes to render said rectifiers alternately conductive in successively occurring half cycles substantially simultaneously with the occurrence of said pulses, means for applying the outputs of said gate controlled rectifiers to said load, and means connected across said load for deriving a unidirectional signal to produce an adjustable transfer characteristic for said load for differing lighting conditions.

Claim 11

The apparatus as claimed in claim 7 which further comprises a second Zener diode having a differing Zener voltage than the first Zener diode and being coupled across said first Zener diode and said variable resistor.

Claim 12

The apparatus as claimed in claim 7 which further comprises means for adjusting said bias for the emitter of said first transistor for providing a voltage at the lamp load for a zero value control signal.