UJT_BATTERY_CHARGER

Published:2009/7/6 4:38:00 Author:May | From:SeekIC

This circuit will not work unless the battery to be charged is connected with proper polarity. The battery voltage controls the charger and when the battery is fully charged, the charger will not supply current to the battery. The battery charging the current is obtained through the SCR when it is triggered into the conducting state by the UJT relaxation oscillator. The oscillator is only activated when the battery voltage is low.VB21 of the UJT is derived from the voltage of the battery to be charged, and since VP=VD=VB21; the higher VB21,the higher Vp. When Vp exceeds the breakdown voltage of the zener diode Z1, the UJT will cease to ftre and the SCR will not conduct. This indicates that the battery has attained its desired charge as set by R2.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Power_Supply_Circuit/UJT_BATTERY_CHARGER.html

Print this Page | Comments | Reading(3)