KitsGuru Battery Charger LGKT114 Educational Electronic Hobby Kit

Here we will consider six applications of SCR like power control, switching, zero-voltage switching, over-voltage protection, pulse circuits and battery charging regulator.The basic components of the circuits are diodes are to establish a full-wave rectified sig¬nal across first SCR and the 12 V battery to be charged. When the battery is in dis¬charged condition, second SCR is in the off-state as will be clear after discussion. When the full-wave rectified input is large enough to give the required turn-on gate current first SCR will turn on and the charging of the battery will commence. At the commencement of charging of battery, voltage VR determined by the simple volt¬age-divider circuit is too small to cause 12.0 V zener conduction. In the off-state Zener diode is effectively an open-circuit maintaining second SCR in the off-state because of zero gate current. Thus the regulator charges the battery whenever the voltage drops and prevents overcharging when fully charged. There are many more applications of SCRs such as in soft start circuits, logic and digital circuits, but it is not possible to discuss all these here.