Hi all
I have recently planned to install solar panels at my home.I have planned to make the charge controller myself.I planned to be it as MPPT controller.For the controller,I will use atmega328p.It ill also have digital readout and some other remote controllable/monitoring functions.But the problem is the buck converter design part.Previously i designed a normal buck using atmega8a and some passive components to charge battery.But the main problem i faced that without no load,the output was getting almost the same as input voltage(inspite of lowering the pwm frequency).But whenever i connected a battery to charge,the converter somehow worked(I was not able to change the voltage very much at the output though) and fulfilled my purpose.My question is

1)How to get a variable voltage at buck converter output without no load?
2)Will a synchronous buck converter resolve this problem?

 

1)How to get a variable voltage at buck converter output without no load?

It needs a load, such as a battery.
Why are you concerned about no load?

Note that you won't be able to change the voltage much when a battery is connected since the battery has a very low impedance.
The main thing that happens when you try to increase the voltage is that the charge current will increase.

2)Will a synchronous buck converter resolve this problem?

No.
But it's not a real problem.

 

It needs a load, such as a battery.
Why are you concerned about no load?

Note that you won't be able to change the voltage much when a battery is connected since the battery has a very low impedance.
The main thing that happens when you try to increase the voltage is that the charge current will increase.
No.
But it's not a real problem.

The problem is,output is getting different with different load connected.That's why,I was asking for the no load solution.So,in this case,how to get the actual output measured?

 

The problem is,output is getting different with different load connected.That's why,I was asking for the no load solution.So,in this case,how to get the actual output measured?

How much difference in voltage with load change?
I would measure it at both the minimum and maximum load current.

 

Ok....I will ready a test setup and let u know the details shortly!!This time I will go with a synchronous version....I have ordered the high side mosfet drivers(IR2104 & IR2110 both).Previously I built it with PMOS.

 

Ok....I will ready a test setup and let u know the details shortly!!This time I will go with a synchronous version....I have ordered the high side mosfet drivers(IR2104 & IR2110 both).Previously I built it with PMOS.

Still doing the project ? Need any help ?

I can help with the project.

 

Still doing the project ? Need any help ?

I can help with the project.

I am ready to test.....Please give me some details!!Sorry for being late