Qaisar Azeemi
Member
Hi all;
Following is the design of my pb-acid battery charger that i've designed to charge 24v, 100AH pb-battries with a current of 10A approx. first i used 10A, 24v
transformer with the circuit but it could deliver 6.3A hardly and the voltages at the transformer o/p terminals also dropped down to 20V so it was unable to charge.
After that i used a 36V, 32A mighty transformer. In the circuit after rectification the voltages boosted up to 50V DC that is quite problemous and
blown out the MOSFET IRF3205, i thought it is blown out due to the reason that it can withstand with a maximum voltages of 55v dc so i used IRF 540 that can
withstand with 100v dc but it is also burn out the same way. the current through the circuit is 10A approx: now my questions are that:
1) why voltages are boosted after rectification?
2) what is the role of power of transformer?
3) why MOSFETS are burning out? as i was fully confident by looking at data sheet that it can withstand with 50v dc? ( i am using mosfet to cutoff after battery
is fully charged, the cutoff circuit is not shown here).
View attachment 67885
Following is the design of my pb-acid battery charger that i've designed to charge 24v, 100AH pb-battries with a current of 10A approx. first i used 10A, 24v
transformer with the circuit but it could deliver 6.3A hardly and the voltages at the transformer o/p terminals also dropped down to 20V so it was unable to charge.
After that i used a 36V, 32A mighty transformer. In the circuit after rectification the voltages boosted up to 50V DC that is quite problemous and
blown out the MOSFET IRF3205, i thought it is blown out due to the reason that it can withstand with a maximum voltages of 55v dc so i used IRF 540 that can
withstand with 100v dc but it is also burn out the same way. the current through the circuit is 10A approx: now my questions are that:
1) why voltages are boosted after rectification?
2) what is the role of power of transformer?
3) why MOSFETS are burning out? as i was fully confident by looking at data sheet that it can withstand with 50v dc? ( i am using mosfet to cutoff after battery
is fully charged, the cutoff circuit is not shown here).
View attachment 67885