Power supply for airfield lighting
Disclosed herein is a power supply suitable for use with an airfield lighting device. In accordance with an example embodiment, there is disclosed herein, a rectifier that converts a signal from an alternating current (AC) current source to a direct current (DC) voltage. The circuit comprises a current sensor, a controller, and a half active bridge rectifier. The controller receives a signal from the current sensor and controls the operation of the half active bridge rectifier to produce a light emitting diode (LED) current based on the current sensed by the current sensor.
1. An apparatus, comprising:
a current sensor for measuring an input current;
a split winding inductor having an input coupled with the current sensor, and an output;
a half active bridge rectifier having a first input coupled with the output of the split winding inductor, a second input, and an output; and
a controller having a first input coupled with the current sensor, a second input coupled with the output of the half active bridge rectifier, and an output coupled with the second input of the half active bridge rectifier;
wherein the controller provides a control signal to the half active bridge rectifier to produce a voltage at the output of the half active bridge rectifier to provide power to at least one light emitting diode.
2. The apparatus of claim 1 , wherein the current sensor is a current transformer.
3. The apparatus of claim 1 , wherein the current sensor is a Hall-effect current sensor.
4. The apparatus of claim 1 , further comprising an isolation transformer for receiving the input current, the isolation transformer providing a current to the current sensor.
5. The apparatus of claim 4 , further comprising at least one capacitor coupled interstitial to the isolation transformer and split winding inductor for isolating high frequency and electro-magnetic interference harmonic conversion signals.
6. The apparatus of claim 1 , wherein the half active bridge rectifier comprises:
two controllable switching devices coupled in a cascade configuration;
a capacitor coupled across one of the controllable switching devices;
wherein the controller switches the controllable switching devices in order to control a voltage across the capacitor.
7. The apparatus set forth in claim 1 , further comprising:
a light source coupled with the controller;
a second input for receiving a signal from an external lighting device;
a phantom load coupled across the second input; and
a signal conditioning circuit coupling the second input to the controller;
wherein the controller synchronizes flashing the light source with the signal received from the second input.
8. The apparatus set forth in claim 7 , wherein the phantom load comprises a triac.
9. The apparatus set forth in claim 7 , wherein the controller is coupled with the phantom load and operable to control the phantom load; and
wherein the controller changes the phantom load in response to detecting the light source is inoperable.
10. The apparatus set forth in claim 7 , wherein the light source is a light emitting diode.
11. The apparatus set forth in claim 7 , further comprising a wireless sensor coupled with the controller;
wherein the controller receives programming instructions for controlling the operation of the light source via the wireless sensor.
12. The apparatus set forth in claim 11 , wherein the wireless sensor is an infra red sensor.
13. An apparatus, comprising:
a current sensor for measuring an input current;
a split winding inductor having an input coupled with the current sensor, and an output;
means for producing a voltage from a current received from the split winding inductor; and
control means for controlling the means for producing a voltage, the control means receives a measurement of the input current from the sensor and provides a control signal to the means for producing a voltage to achieve an output voltage based on the measurement of the input current.
14. The apparatus set forth in claim 13 , further comprising:
a light source coupled with the control means;
a second input for receiving a signal from an external lighting device; and
means for providing a phantom load coupled across the second input; and
wherein the controller means flashes the light source in synchronization with the signal received from the second input.
15. The apparatus set forth in claim 13 , further comprising a means for sensing a wireless signal coupled with the control means;
wherein the control means receives programming instructions for controlling the operation of the light source via the means for sensing a wireless signal.