Fluorescent lamp assembly having multiple settings and method

Abstract

A fluorescent lamp assembly includes a fluorescent lamp ballast capable of detecting at least one of a plurality of input signals and generating an output signal. The output signal is associated with a power level that is based on the at least one detected input signal. The fluorescent lamp assembly also includes a fluorescent lamp capable of receiving the output signal and generating light. An intensity of the light is based on the power level associated with the output signal.

What is claimed is: 
     
       1. A method, comprising:
 detecting at least one of a plurality of input signals at a fluorescent lamp ballast; 
 selecting an operating frequency of the fluorescent lamp ballast by generating at least one a plurality of control signal signals based on the at least one detected input signal and setting at least one of a resistance and a capacitance in a resistor-capacitor (RC) network based on the at least one of the control signal signals, the RC network affecting the operating frequency of the fluorescent lamp ballast; and 
 providing power to a fluorescent lamp based on the operating frequency of the fluorescent lamp ballast, the fluorescent lamp capable of generating light having an intensity that is based on the power provided to the fluorescent lamp. 
 
     
     
       2. The method of  claim 1 , wherein selecting the operating frequency comprises:
 generating a signal at an oscillator based on the at least one control signal, the signal having the operating frequency, the oscillator comprising the RC network. 
 
     
     
       3. The method of  claim 2 , wherein providing power to the fluorescent lamp comprises:
 amplifying the signal generated by the oscillator to produce an amplified signal; 
 generating a voltage signal using the amplified signal; and 
 providing the voltage signal to the fluorescent lamp, the voltage signal providing the power to the fluorescent lamp. 
 
     
     
       4. The method of  claim 1 , further comprising:
 selecting a second operating frequency of the fluorescent lamp ballast; and 
 providing a different power to the fluorescent lamp based on the second operating frequency of the fluorescent lamp ballast, the fluorescent lamp capable of generating light having a second intensity based on the different power. 
 
     
     
       5. The method of  claim 1 , wherein further comprising:
 within the RC network comprises, coupling each of a plurality of capacitors, each capacitor coupled to one of a plurality of transistors, each transistor having a gate operable to receive one of a the plurality of control signals; and 
 selecting the operating frequency of the fluorescent lamp ballast comprises by setting an overall capacitance in the RC network by enabling one or more of the transistors. 
 
     
     
       6. A method, comprising:
 detecting at least one of a plurality of input signals received at a fluorescent lamp ballast including a plurality of sample and hold circuits and a decoder, each of the sample and hold circuits configured to output a value identifying a presence or absence of one of the input signals;   generating an output signal, the output signal associated with a power level that is based on a plurality of control signals generated by the decoder based on the values from the sample and hold circuits; and   receiving the output signal at a fluorescent lamp configured to generate light, wherein an intensity of the light is based on the power level associated with the output signal.   
     
     
       7. The method of claim 6, wherein each combination of the plurality of input signals corresponds to a different power level and the fluorescent lamp ballast is configured to generate an output signal for each of the different power levels. 
     
     
       8. The method of claim 6, wherein a detector within the fluorescent lamp ballast is configured to detect the at least one of the plurality of input signals, the detector comprising the sample and hold circuits and the decoder, the method further comprising:
 generating a signal at an oscillator having a frequency based on at least one of the control signals.   
     
     
       9. The method of claim 8, further comprising:
 amplifying the signal generated by the oscillator to produce an amplified signal; and   generating the output signal in a tank circuit using the amplified signal.   
     
     
       10. The method of claim 9, wherein the fluorescent lamp ballast includes a power amplifier amplifying the signal, and wherein the tank circuit comprises an inductor-capacitor resonant tank circuit. 
     
     
       11. The method of claim 8, wherein the frequency of the signal generated by the oscillator is based on at least one of the control signals. 
     
     
       12. The method of claim 11, wherein each of the control signals is configured to adjust at least one of: a capacitance in the oscillator, a resistance in the oscillator, an adjustable current source used to charge a capacitance in the oscillator, and a control voltage used by the oscillator, and wherein the oscillator generates the signal such that the frequency of the signal is based on at least one of: the capacitance in the oscillator, the resistance in the oscillator, a current provided by the adjustable current source, and the control voltage. 
     
     
       13. The method of claim 7, wherein the plurality of control signals adjust the capacitance in the oscillator, wherein the oscillator comprises a plurality of transistors coupled to a plurality of capacitors, the transistors having gates each configured to receive one of the plurality of control signals. 
     
     
       14. The method of claim 6, wherein the plurality of input signals comprise alternating current input voltages. 
     
     
       15. A method, comprising:
 detecting at least one of a plurality of input signals using a plurality of sample and hold circuits and a decoder, each of the sample and hold circuits configured to output a value identifying a presence or absence of one of the input signals, the decoder configured to generate a plurality of control signals based on the values from the sample and hold circuits;   generating a signal having a frequency based on the control signals and responsive to the at least one detected input signal;   amplifying the signal to produce an amplified signal;   generating an output signal using the amplified signal; and   providing the output signal to a fluorescent lamp, the output signal associated with a power level that is based on the frequency of the amplified signal, the fluorescent lamp configured to receive the output signal and generate light, wherein an intensity of the light is based on the power level associated with the output signal.    
     
     
       16. The method of claim 15, further comprising:
 detecting the at least one of the plurality of input signals by detecting whether a first input voltage is present on a first input and detecting whether a second input voltage is present on a second input.   
     
     
       17. The method of claim 16, wherein the sample and hold circuits comprise:
 a first flip-flop configured to output a first value indicating whether the first input voltage is present on the first input; and   a second flip-flop configured to output a second value indicating whether the second input voltage is present on the second input.   
     
     
       18. The method of claim 17, wherein the control signals adjust at least one of: a capacitance in an oscillator generating the signal, a resistance in the oscillator, an adjustable current source used to charge a capacitance in the oscillator, and a control voltage used by the oscillator. 
     
     
       19. The method of claim 18, wherein the control signals adjust the capacitance in the oscillator, and wherein the oscillator comprises a plurality of transistors coupled to a plurality of capacitors, the transistors having gates configured to receive the plurality of control signals, wherein a capacitance provided by the plurality of capacitors is varied using the control signals and the plurality of transistors. 
     
     
       20. The method of claim 19, wherein the oscillator further comprises a plurality of comparators configured to compare a charge stored on the plurality of capacitors to a plurality of reference voltages and a flip-flop configured to receive outputs from the plurality of comparators and generate the signal.