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US 6,486,616 B1Granted
Dual control dimming ballast
AssigneeOsram Sylvania Inc.
InventorsGuang Liu, Sameer Sodhi
Life of this patent
Estimating the term…
Abstract
A dimming ballast apparatus comprises at least one power line dimming control input and at least one non-power-line dimming control input. In a preferred embodiment, the apparatus comprises a firing-angle-to-pulse-width-modulation converter responsive to the power line dimming control input, a voltage-to-pulse-width-modulation converter responsive to the non-power-line dimming control input, a low-pass filter responsive to the firing-angle-to-pulse-width-modulation converter and the voltage-to-pulse-width-modulation converter, and a dimming ballast circuit having a dim level command input responsive to the low-pass filter.
Claims8
A dimming ballast apparatus comprising:
- a first DC input;
- a second DC input;
- a first capacitor which couples the first DC input to the second DC input;
- a first transistor having a base, a collector and an emitter, the collector coupled to a supply line;
- a series combination of a first resistor and a second resistor which couples the base of the first transistor to the supply line;
- a diode having a cathode coupled to the first DC input and an anode coupled to the base of the first transistor;
- a first zener diode coupling a junction of the first resistor and the second resistor to a control ground;
- a second transistor having a gate coupled to the junction of the first resistor and the second resistor, a drain coupled to the second input, and a source coupled to control ground;
- a series combination of a third resistor and a fourth resistor which couples the emitter of the first transistor to control ground;
- a pulse width modulation circuit having an input and an output, the input coupled to a junction of the third resistor and the fourth resistor;
- an optocoupler having an input coupled to the output of the pulse width modulation circuit, an emitter output coupled to a ballast ground, and a collector output;
- a series combination of a second zener diode and a fifth resistor which couples the collector output of the optocoupler to a supply line;
- a rectifier coupleable to a power line;
- a firing-angle-to-pulse-width-modulation converter coupled to the rectifier;
- a third transistor having a base coupled to an output of the firing-angle-to-pulse-width-modulation converter, a collector coupled to the collector output of the optocoupler, and an emitter coupled to ballast ground;
- a low-pass filter coupled to the collector output of the optocoupler;
- and
- an inverter circuit coupled to the rectifier, the inverter circuit having a dim level command input responsive to the low-pass filter.
15 more elements
A dimming ballast apparatus comprising:
- a dimming regulation circuit having a first DC input and a second DC input;
- a rectifier coupleable to a power line;
- a firing-angle-to-pulse-width-modulation converter coupled to the rectifier;
- an optocoupler having an input coupled to the firing-angle-to-pulse-width-modulation converter, an emitter output coupled to a control ground, and a collector output;
- a first resistor which couples the collector output of the optocoupler to a supply line;
- a first capacitor which couples the collector output of the optocoupler to control ground;
- a transistor having a base, a collector, and an emitter, the emitter coupled to control ground;
- a second resistor which couples the collector output of the optocoupler to the base of the transistor;
- a third resistor which couples the collector of the transistor to the supply line;
- a series combination of a fourth resistor, a first diode and a second diode, which couples the collector of the transistor to the first input of the dimming regulation circuit;
- a second capacitor which couples the junction of the first diode and the second diode to control ground;
- an inverter circuit coupled to the rectifier, the dimmable inverter circuit having a dim level command input;
- and
- an optocoupler which couples the dimming regulation circuit to the dim level command input of the inverter circuit.
11 more elements
A dimming ballast apparatus, comprising:
- at least one power line dimming control input;
- at least one non-power-line dimming control input;
- a firing-angle--to- pulse-width-modulation converter responsive to t hie power line dimming control input;
- a voltage-to-pulse-width-modulation converter responsive to the non-power--line chiming control input;
- a low-pass filter responsive to the firing-angle-to-pulse-width-modulation converter and the voltage-to-pulse-width-modulation converter;
- a dimming ballast circuit having a dim level command input responsive to the low-pass filter;
- and
- wherein the at least one non-power-line dimming control input comprises a first input and a second input, and wherein the voltage-to-pulse-width-modulation converter comprises:
- a capacitor which couples the first input to the second input;
- a first transistor having a base, a collector and an emitter, the collector coupled to a supply line;
- a series combination of a first resistor and a second resistor which couples the base of the first transistor to the supply line;
- a diode having a cathode coupled to the first input and an anode coupled to the base of the first transistor;
- a zener diode coup ling a junction of the first resistor and the second resistor to a control ground;
- a second transistor having a gate coupled to the junction of the first resistor and the second resistor, a drain coupled to the second input, and a source coupled to control ground;
- a series combination of a third resistor and a fourth resistor which couples the emitter of the first transistor to control ground;
- and
- a pulse width modulation circuit having an input coupled to a junction of -he third resistor and the fourth resistor.
14 more elements
A dimming ballast apparatus, comprising:
- at least one power line dimming control input;
- at least one non-power-line dimming control input;
- a firing-angle-to-pulse-width-modulation converter responsive to the power line dimming control input;
- an optocoupler having an input coupled to the firing-angle-to-pulse-width-modulation converter, an emitter output coupled to a control ground, and a collector output;
- a first resistor which couples the collector output of the optocoupler to a supply line;
- a first capacitor which couples the collector output of the optocoupler to control ground;
- a transistor having a base, a collector, and an emitter, the emitter coupled to control ground;
- a second resistor which couples the collector output of the optocoupler to the base of the transistor;
- a third resistor which couples the collector of the transistor to the supply line;
- a series combination of a fourth resistor, a first diode and a second diode, which couples the collector of the transistor to the non-power-line dimming control input;
- and
- a second capacitor which couples the junction of the first diode and the second diode to control ground.
9 more elements
A dimming ballast apparatus, comprising:
- at least one power line dimming control input;
- at least one non-power-line dimming control input;
- a firing-angle-to-pulse-width-modulation converter responsive to the power line dimming control input;
- a low-pass filter responsive to the firing-angle-to-pulse-width-modulation converter;
- a dimming regulation circuit responsive to the low-pass filter and the non-power-line dimming control input;
- an inverter circuit having a dim level command input responsive to the dimming regulation circuit;
- and
- an optocoupler which couples the fir ing-angle-to-pulse-width-modulation converter to the low--pass filter.
5 more elements
A dimming ballast apparatus, comprising:
- at least one power line dimming control input;
- at least one non-power-line dimming control input;
- a firing-angle-to-pulse-width-modulation converter responsive to the power line dimming control input;
- a low-pass filter responsive to the firing-angle-to-pulse-width-modulation converter;
- a dimming regulation circuit responsive to the low-pass filter and the non-power-line dimming control input;
- an inverter circuit having a dim level command input responsive to the dimming regulation circuit;
- and
- an optocoupler which couples the dimming regulation circuit to the dim level command input of the inverter circuit.
5 more elements
A dimming ballast apparatus, comprising:
- at least one power line dimming control input;
- at least one non-power-line dimming control input;
- a firing-angle-to-pulse-width-modulation converter responsive to the power line dimming control input;
- a voltage-to-pulse-width-modulation converter responsive to the non-power-line dimming control input;
- a low-pass filter responsive to the firing-angle-to-pulse-width-modulation converter and the voltage-to-pulse-width-modulation converter;
- a dimming ballast circuit having a dim level command input responsive to the low-pass filter;
- and
- an optocoupler which couples the voltage-to-pulse-width-modulation converter to the low-pass filter.
5 more elements
Dependencies are inferred from the claim text.