Simulation of Automatic Cut-Off 12V Battery Charger
Karna, Nikita (2019)
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2019112722987
https://urn.fi/URN:NBN:fi:amk-2019112722987
Tiivistelmä
The objective of this project was to simulate a charger for 12V battery which will have the function to automatically cut-off the charging when the battery is fully charged. When the battery is fully charged to its capacity, the charging voltage must be disconnected, otherwise the battery will be overcharged. Overcharging a battery shortens the lifetime of the battery severely, and there is risk of excessive gas forming inside the battery which warps the cas-ing of the battery. Such battery should not be used, as this may cause an operational haz-ard.
The main components used in this automatic battery charger are the bridge rectifier circuit, the LM317 linear voltage regulator and the LM311 voltage comparator. The LM317 voltage regulator was used to convert the rectified DC voltage to a constant output voltage which is used to charge the battery. Once the battery is completely charged the LM311 voltage com-parator is used to drive the circuitry which will cut-off the charging voltage and protect the battery from overcharging.
While working on this project the circuit was first divided into small individual ‘modules’, such as AC to DC conversion, producing constant steady output voltage, creating the cut-off logic to turn off the charging when the battery is full. These ‘modules’ was created in Multisim simulation tool to verify that each component was working as expected. Finally, all the ‘mod-ules’ were assembled to create a battery charging circuit with automatic cut-off.
This project has simulated the automatic charging cut-off of the battery when it was fully charged by comparing the voltage of the battery with a reference voltage, preventing the overcharging of the battery.
The main components used in this automatic battery charger are the bridge rectifier circuit, the LM317 linear voltage regulator and the LM311 voltage comparator. The LM317 voltage regulator was used to convert the rectified DC voltage to a constant output voltage which is used to charge the battery. Once the battery is completely charged the LM311 voltage com-parator is used to drive the circuitry which will cut-off the charging voltage and protect the battery from overcharging.
While working on this project the circuit was first divided into small individual ‘modules’, such as AC to DC conversion, producing constant steady output voltage, creating the cut-off logic to turn off the charging when the battery is full. These ‘modules’ was created in Multisim simulation tool to verify that each component was working as expected. Finally, all the ‘mod-ules’ were assembled to create a battery charging circuit with automatic cut-off.
This project has simulated the automatic charging cut-off of the battery when it was fully charged by comparing the voltage of the battery with a reference voltage, preventing the overcharging of the battery.