suppliers of QL8X12B-1PL68I and PDF data of QL8X12B-1PL68I

STROBE FLASHER APPLICATION Be sure to remember the following points when designing series type automatic strobe flashers using the CR3JM or CR3AMZ. 1. Rated repetitive peak on-state current ITRM The figure shows a turn-off characteristic test circuit. When a repetitive discharge current passes to the thyristor (TUT) through the load from the charged main capacitor (CM), the limiting value for the on-state peak current the thyristor can withstand is the rated repetitive peak on-state current. To ensure the current fed into the thyristor will not exceed this rated value, it is essential to select the appropriate main capaci- tor charging voltage VCM, the load (Xenon lamp) resistance and the anode reactor L described below. 2. Main capacitor CM In addition to its effect on the peak on-state current value, the capacitance of the main capacitor is an important factor deter- mining the temperature rise of the thyristor junction. When the capacitance of the main capacitor becomes large, the dis- charge-time constant becomes great also, the temperature rise at the thyristor junction will be very serious and the commutating capability of the thyristor will decrease. When the device is turned off, damage may also be caused by the reverse voltage applied to the thyristor resulting in thermal run away. 3. Commutating Capacitor Cc The capacitance values of the commutating Capacitor (Cc) re- quired for turning the thyristor off can be obtained from the fol- lowing equation since the electric charge stored in this capacitor and the electric charge released during commutation are the same.