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US 11,208,131 B2Granted
Systems and methods for controlling railroad highway crossing flashers
AssigneeBNSF Railway Company
InventorRalph Young
Life of this patent
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Abstract
A railroad crossing warning circuit includes a lamp and a signal generator for generating a first signal of a selected frequency. Divider circuitry divides the frequency of the signal to generate second signal at a flashing frequency. A switch responsive to the second signal controls current flow through the lamp and cause the lamp to flash at the flashing frequency.
Claims20
A railroad crossing warning circuit comprising:
- a lamp;
- a signal generator for generating a first signal of a selected frequency;
- divider circuitry for dividing the selected frequency of the first signal to generate second signal having a flashing frequency, the divider circuitry comprising first and second complementary outputs;
- and
- a switch responsive to the second signal for controlling current flow through the lamp to selectively cause the lamp to flash at the flashing frequency.
2 more elements
A railroad crossing flasher system comprising:
- first and second lamps;
- first control circuitry for controlling flashing of the first lamp comprising:
- a first signal generator for generating a first base signal having a frequency;
- a first frequency divider for dividing the frequency of the first base signal to generate a first flashing signal having a flashing frequency;
- and
- a first switch responsive to the first flashing signal for controlling current flow through the first lamp to selectively cause the first lamp to flash at the flashing frequency;
- and
- second control circuitry for controlling flashing of the second lamp comprising:
- a second signal generator for generating a second base signal having a frequency;
- a second frequency divider for dividing the frequency of the second base signal to generate a second flashing signal having the flashing frequency;
- and
- a second switch responsive to the second flashing signal for controlling current flow through the second lamp to selectively cause the second lamp to flash at the flashing frequency, wherein the first and second flashing signals are out-of-phase such that the first and second lamps alternately flash.
9 more elements
A crossing gate lamp control system comprising:
- first and second crossing gate lamps;
- a signal generator for generating a first signal of a selected frequency;
- divider circuitry for dividing the selected frequency of the first signal to generate first and second complementary output signals each at a flashing frequency;
- a first switch responsive to the first complementary output signal for controlling current flow through the first crossing gate lamp to selectively cause the first crossing gate lamp to flash at the flashing frequency;
- and
- a second switch responsive to the second complementary output signal for controlling current flow through the second crossing gate lamp to selectively cause the second crossing gate lamp to flash at the flashing frequency alternately with the flashing of the first crossing gate lamp.
3 more elements
Dependencies are inferred from the claim text.