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Neon sign i.e. neon character, has memory storing signal representative of initial brightness of LEDs, and control device controlling current supply device for LEDs so that actual value is brought closer to target value
Neon sign i.e. neon character, has memory storing signal representative of initial brightness of LEDs, and control device controlling current supply device for LEDs so that actual value is brought closer to target value
The sign has a brightness sensor (8) measuring light intensity produced by LEDs (7). A memory stores a signal representative of initial brightness of the LEDs. An actual output signal of the sensor is supplied as an actual signal. The signal stored in the memory is supplied as a target-signal. A control device (11) controls a current supply device (9) for the LEDs so that an actual value is brought closer to the target value. Another memory stores a set of characteristic curves describing aging behavior of the LEDs under influence of parameters detected by a temperature sensor (13).
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