U243B

· Can be protected against damage or interference with a minimum of external circuitry
· Temperature- and voltage-compensated frequency
· Warning indication of lamp failure by means of frequency doubling
· Voltage dependence of the car indicator lamps also compensated for lamp failure
· Relay output with high-current carrying capacity and low saturation voltage

Flashing generator, operation with smaller loads ( 2 W)

By adding a resistor to the application circuit (figure 1), defined operation with lamp loads . 2 W is possible. The
voltage drop across the resistor R₄ is generated by the current flowing over the relay and should be about 15 mV. With a relay current of 150 mA (relay resistance 73 Q), this requires a resistance of R₄ = 100 m. The change of the operating point by 15 mV results in a corresponding change of the control signal threshold by 15 mV. For a lamp current of 2.7 A, a measuring resistance of
         81 mV 15 mV
R₃ = --------------------   = 25 m results.
                2.7 A