Abstract: A side-emitting lens for use with an LED lamp provides a distribution of emitted light that is substantially normal to an axis of symmetry of the lens; the light can also be symmetrical with respect to a plane normal to the lens axis. The lens has a cavity in which the LED lamp can reside, having a cavity refracting surface with a central section and a stepped cavity sidewall. The lens also has a base external refracting surface surrounding the cavity, an internal reflecting surface spaced apart from the cavity, and a side surface; these surfaces redirect light that enters the lens through the cavity refracting surface. For many applications, the lens axis is vertical in service and the lens is configured to provide a narrow distribution of light in the horizontal plane.

Abstract: A side-emitting lens for use with an LED lamp provides a distribution of emitted light that is substantially normal to an axis of symmetry of the lens; the light can also be symmetrical with respect to a plane normal to the lens axis. The lens has a cavity in which the LED lamp can reside, having a cavity refracting surface with a central section and a stepped cavity sidewall. The lens also has a base external refracting surface surrounding the cavity, an internal reflecting surface spaced apart from the cavity, and a side surface; these surfaces redirect light that enters the lens through the cavity refracting surface. For many applications, the lens axis is vertical in service and the lens is configured to provide a narrow distribution of light in the horizontal plane.

Abstract: A voltage regulator and switching circuit for a flash lamp control unit. A silicon transistor is used to switch on an incandescent lamp and to regulate the voltage across the lamp. A driver transistor is connected to the switch transistor in a darlington connection with the collectors connected by a diode. During initial turn on of the lamp, its filament draws a heavy current furnished by the darlington circuit. As the filament heats, its current drops to a low value. Drive current then flows through the drive transistor and a resistor to ground, reverse biasing the diode and changing the circuit to a single transistor circuit. The driver transistor is controlled by a differential amplifier having a first transistor biased by a first voltage divider network connected across the power supply and a second transistor biased by a second voltage divider network connected across the regulated voltage.

Abstract: A flasher unit for buoys, beacons and the like for flashing an incandescent lamp in a required sequence of short and long flashes having short or long eclipses between flashes. A counter is provided having a number of counts equal to the number of flash-eclipse pairs required. A timing pulse generator is selectively controlled to produce timing pulses during each count that are temporally spaced in accordance with the flash-eclipse time durations during each count. Certain ones of the timing pulses serve to clock the counter. Lamp control pulses are generated during each count for energizing the lamp for the preselected time duration. A sync pulse is generated at the beginning of every flash and a second pulse during the first flash in a sequence. These pulses are externally available and are communicated to other flasher units for synchronization. The unit will also synchronize to incoming sync pulses. A photocell circuit inhibits flashing during daylight periods.