The submit talks about a single High current transistor based lead acid battery charger circuit with an automatic over charge cut off feature.
Yes it is going to function which enables it to quit charging the battery when around 14 V is attained across the battery terminals.
but I am doubtful about the 1 ohm base resistor value…it ought to be determined correctly.
The transistor and the IC both might be installed on a common heatsink utilizing mica separator kit. This may benefit from the thermal protection feature of the IC and will help protect both the devices from overheating.
The presented single transistor high current battery charger is a simple way of charging a battery and also accomplishing an auto shut off when the battery reaches a full charge level.
The circuit is really a clear-cut common collector transistor stage making use of the demonstrated 2N6292 power device.
The design is furthermore introduced as an emitter follower and as the term indicates the emitter follows the base voltage and permits the transistor to conduct only providing the emitter potential is 0.7V lower that the utilized base potential.
In the demonstrated diagram, the base of the transistor is given with a controlled 15 V from the IC 7815, which guarantees a potential improvement of about 15 – 0.7 = 14.3 V across the emitter/ground of the transistor.
The diode is not needed and ought to be taken off the base of the transistor to be able to reduce an unneeded drop of an extra 0.7 V.
The above voltage also turns into the charging voltage for the associated battery across these terminals.
While the battery charges and its terminal voltage remains to be below the 14.3 V mark, the transistor base voltage keeps carrying out and providing the essential charging voltage to the battery.
In spite of this the moment the battery starts achieving the full and above 14.3 V charge, the base is inhibited from a 0.7 V drop across its emitter which forces the transistor to stop executing and the charging voltage is cut off to the battery for the present time, whenever the battery level commences going below the 14.3 V mark, the transistor is turned on again…the cycle keeps repeating being sure a safe charging fr the hooked up battery.
Base resistor = Hfe x battery internal resistance