24V (upto 4A) battery charger design with auto cutt off

dear all
I need to design a 24V battery charger.
Amperes could be 4A max.
could I design it using LM317K or some other thing?

shahbaz.ele said:

dear all
I need to design a 24V battery charger.
Amperes could be 4A max.
could I design it using LM317K or some other thing?

Click to expand...

Do not use analogue regulators at 4 amps 24V.
A voltage drop let’s say 30-24=6V create a heater from 4 x 6 = 24 Watt.
Use a switched supply easy to create from a small Pic, coil, powerfet and one opamp to regulate the current. A 16Fxxx with analogue inputs will do.
Measure voltage, measure current and regulate the PWM to the gate of the power fet.

dear can you give block diagram of this scheme.
or some circuit designed of this type

shahbaz.ele said:

dear all
I need to design a 24V battery charger.
Amperes could be 4A max.
could I design it using LM317K or some other thing?

Click to expand...

A simple block attached you only have to calculate values.
This is simple and at a low level mathematical/electronica level.
good luck

dear you may forgot to attach figure.

shahbaz.ele said:

dear you may forgot to attach figure.

Click to expand...

You should have it now.

- - - Updated - - -

shahbaz.ele said:

dear you may forgot to attach figure.

Click to expand...

http://obrazki.elektroda.pl/3025170100_1375687546.jpg

dear picbuster
.jpg image still not opening.

shahbaz.ele said:

dear all
I need to design a 24V battery charger.
Amperes could be 4A max.
could I design it using LM317K or some other thing?

Click to expand...

You can to use LM338K TO-3, its 5A linear voltage regulator. This regulator is very reliable. Of course if you look to make power efficient device you can try with switching voltage regulator.


For two lead acid batteries with nominal 12V voltage, float charging voltage is 27,6V and cycling voltage is 28,8V.

Lets say that you need at least 3V Vi-Vo difference, Vi (float voltage) should be 30,6V and Vi (cycling voltage) should be 31,8V.

Power dissipation for LM338K in 3V difference and at 5A is 15W, which this regulator handle without problem, efficiency is other story.

For LM338K TO-3 maximum input voltage is up to 35V and maximum dissipation power is up to 50W.
For LM338T TO-220 maximum input voltage is up to 35V and maximum dissipation power is up to 25W.


I use LM338K regulator a lots for battery chargers, I can say its very reliable and almost undestructable if you make all properly.



Best regards,
Peter

but what is the input voltage of battery charger does it powered from mains 230v or any other volt

24V (upto 4A) battery charger design with auto cutt off

dear all
I need to design a 24V battery charger.
Amperes could be 4A max.
could I design it using LM317K or some other thing?

Click to expand...

Input is from mains 220VAC.

shahbaz.ele said:

Input is from mains 220VAC.

Click to expand...

This doesnt change situation, you should use transformer or SMPS design to lower voltage, rest is the same.


Best regards,
Peter