No. 4944-6/7

LB1668, LB1668M, LB1667, LB1667M

1. While the blades are turning, the capacitor is charged with a current of about 3 µA (typical), and C is discharged by

pulses that correspond to the motor speed.

2. When the blades lock, the capacitor is no longer discharged, and the voltage across the capacitor increases. The

output is turned off when that voltage reaches 0.8

× V

3. When the output is turned off, the capacitor is discharged at about 0.44 µA (typical). When the capacitor voltage falls

turned on at this time.) These operations, i.e. items 2. and 3., are repeated with a ton:toff ratio of about 1:6 to protect

the motor.

on.

Automatic Recovery Circuit C-Pin Voltage