charger circuit for 12v 150ah battery

[--BawA--]

i want to design a charger using forward converter. i intend to use UC3842 chip as a control circuit , I just wanted to know is it possible to control the current ? I mean charger should be able to adjust the output current and voltage ? is it possible from uc3842??

configuration
input voltage 90VAC to 265VAC
output voltage 13.6 to 14VDC (adjustable)
output current 15 Ampere (adjustable)

is it possible to adjust these parameters using a pot?

 

[Truedeal]

Yes.

http://www.soloelectronica.net/PDF/AppNote03.pdf

Just modify the circuits in the above application notes.

One company I worked for used pwm chips for military applications and had always utilized current sensing for voltage regulation. Which meant if the board was powered up with out a minimum load the magic smoke would be forcefully ejected from the IRF-150 fets.
Several designs we had we switched over voltage regulation and those were minor modifications. The power supply noise had been reduced as well.

 

[--BawA--]

I have seen some circuits in which an external opamp was used for limiting the current, so how that opamp is used for adjusting the current?

 

[Truedeal]

The opamp would have to read the voltage drop across a shunt resistor. You could set it for a maximum of your choosing and even have a front panel pot adjustment. I would use a ten turn pot with a vernier knob.

 

[--BawA--]

could you please post any schematics with working operations?

 

[Truedeal]

I wish I could. I just bought this computer and my old schematic drawing program will not run on it. I have thousands of schematics and mechanical drawings in the Visio programs.

Anybody have a heavily discounted VISIO program for windows 8.1 in the 64 bit format?

No answers for pirated software please. My wife works for a Federal Law Enforcement agency and my computer may be inspected at any time with out a warrant.

 

[--BawA--]

thanks truedeal for your reply
i wanted to ask " In UC3842 there is a current sense pin , so why do we need an external opamp to adjust current , ?

 

[Truedeal]

I was referring the op amp that would be used to sense the current. Is the current sense one lead of the primary dropped through a coil to act as a transformer? In any case your project is doable.