Arduino and solar Panel, detection of power

Using Arduino Project Guidance
1

Hi :slight_smile:
I need a circuit do measure with the arduino uno the voltage of a solar panel.
I´m using a load resistance of 200ohm and a paralell of 20k ohm.
But before i connetc my existing circuit to arduino, i need to use a operational amplifier, but i don´t know how to.
Best regards :slight_smile:
Please i need help is urgent. Ty

2

Why do you "need to use" an operational amplifer?

Is this person one of your classmates?

3

Yes it is.
By the way, we were together when we posted here :slight_smile:

4

What is the open circuit voltage and the short circuit current of your solar panel?

Note that this is not an Arduino project. You can measure the power using a multimeter to measure both the voltage and the current under load.

5

At this moment my circuit has a load resistor of 200 ohm in paralell with two series resostors each one with 20k ohm.
PS: my solar panel specs are: 8.2V, 100mA, 55W at the best scenario.
jremington your sugestion to my colleague it was that for the voltage we just need a voltage divider and fot the current we need to use amplifiers, am i correct?
I don´t know if you´ve already seen my colleague´s picture of the circuit in his post, but it would be great if you could give your opinion about it.

6

What is the open circuit voltage and the short circuit current of your solar panel?

It cannot be a 55 watt panel.

7

Hi
Is this your circuit?

17988143fd944c3f9b1b08be1a3666106c8bd0da.jpg
17988143fd944c3f9b1b08be1a3666106c8bd0da.jpg922×692 26.5 KB

R8 and R9 would be better a 15K and 5K, and have a 0.1uF Bypass Capacitor fitted.
LM741 are old and not suitable for your application, try LM324, quad pack and use a single rather than double ended supply.

Can you tell us your electronics, programming, Arduino, hardware experience?

If this is a school/college/university project you should have lecturers and tutors who can help you with the basics.

Thanks.. Tom.. :slight_smile:

8

This is a university project.
The purpose is measure the current, the voltage, the luminosity and the temperature of a solar panel.
But in your opinion the circuit of the picture is suitable to the purpose of measure the voltage and the current?
By the way, the power of my solar panel is 0.5W at the best case scenario.
Another of my colleagues suggested me that i should use a operational amplifier after the voltage divider, but i don´t think that it makes sense.