UAA1041B

The UAA1041B is designed to drive the direction indicator flasher relay. Figure 2 shows the typical system configuration with the external components. UAA1041B consists of a network (R1,C1) to determine the oscillator frequency, shunt resistor (RS) to detect defective bulbs and short circuits in the system, and two current limiting resistors (R2/R3) to protect the IC against load dump transients. The circuit can be used either with or without short circuit detection, and features overvoltage,defective lamp and short circuit detection.

The lightbulbs L2, L3, L4, L5 are the turn signal indicators with the dashboardlight L6. When switch S1 is closed, after a time delay of t1 (in our example t1 = 75 ms), the relay of UAA1041B will be actuated. The corresponding lightbulbs (L2, L3 or L4, L5) will flash at the oscillator frequency, independent of the battery voltage of 8.0 V to 18 V. The flashing cycle stops and the circuit UAA1041B is reset to the initial position when switch S1 is open.