Electronic power controller
AssigneeSystems and Service International, Inc.
InventorsNian Chen, Dudley G. Boyd
Life of this patent
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Abstract
An electrical power controller includes a boost converter, an invertor and an output section. The boost converter includes a control circuit which charges a capacitance from an inductance in accordance with a stream of pulses having a variable duty cycle. A feedback circuit responsive to the power consumed by a load provides an error signal for varying the duty cycle of the pulses. In the invertor, a pair of switches sample the charge on the capacitor to create an AC signal which is introduced to the output section. The sampling frequency in the boost converter is related to the sampling frequency in the invertor by an integer.
Claims27
Apparatus for controlling the illumination of a discharge lamp having a particular impedance, the apparatus comprising:
- means for introducing electrical power to the discharge lamp, the power being characterized by a voltage and a frequency and at least the voltage of the electrical power being variable;
- means for ramping the voltage of the electrical power upwardly to a particular magnitude sufficient to fire the discharge lamp;
- and
- a control circuit responsive to the firing of the discharge lamp at the particular magnitude of the voltage for varying the voltage of the electrical power after the discharge lamp has fired thereby reducing the operating power of the discharge lamp.
A ballast for controlling the operation of a discharge lamp having characteristics including a firing voltage and a minimum running voltage, comprising:
- a source of power providing a voltage with characteristics including a variable amplitude;
- means for applying the voltage to the lamp and for increasing the magnitude of the applied voltage from a magnitude less than the firing voltage to a magnitude equal to at least the firing voltage;
- means responsive to the firing of the lamp for providing a particular signal having characteristics indicative of the firing of the lamp;
- and
- the source being responsive to the particular signal of the providing means for reducing the magnitude of the applied voltage to the particular magnitude less than the firing voltage but greater than the minimum running voltage.
Apparatus for controlling the illumination of a discharge lamp in an environment characterized by a temperature, the apparatus comprising:
- means for introducing an alternating current voltage across the lamp, the voltage having a variable magnitude;
- means for increasing the voltage across the lamp to a particular magnitude sufficient to fire the lamp, the particular magnitude of the voltage being dependent upon the temperature of the environment;
- whereby
- the lamp is fired with a voltage not greater than that required to fire the lamp in the environment.
An electrical power controller providing a rapid response to fluctuating power requirement of a load, comprising:
- a source of electrical power;
- induction means coupled to the source and having properties for storing electrical energy;
- capacitor means for storing an electrical charge;
- a control circuit coupled between the induction means and the capacitance means, the control circuit releasing the electrical energy from the induction means to the capacitance means in the form of pulses having a variable duty cycle;
- an inverter responsive to a the electrical charge across the capacitance means for providing an output signal to the load;
- means responsive to the power consumed by the load for providing an error signal;
- and
- means responsive to the error signal for varying the duty cycle of the pulses.
A two stage power controller, including:
- a first stage comprising a boost converter having a capacitor with a charge which provides a first output signal;
- means included in the first stage for charging the capacitor with a series of first pulses having a first frequency;
- a second stage comprising an inverter having a second output signal for powering the load;
- means included in the second stage and responsive to the first output signal of the first stage for energizing the inverter with a series of second pulses having a second frequency;
- and
- the first frequency of the first pulses being an integer multiple of the second frequency of the second pulses.
Dependencies are inferred from the claim text.