I have went up to 15 V and the voltage error remained the same voltage error was about 14.85 at 15V which is much better. I guess the problem was just messy connections I had though 80mV error is still remaining unknown

Another problem I have realised is that I might have problems with my voltage regulators. I use 7805 1.5A 25V maximum regulator. But even at 15V , 100mA it got very very hot ( burned my finger to touch) . I cannot Imagine this regulator running my circuit at 20V and 300mA there is no way

 

hi 321,
I am looking forward to receiving my INA's so that I can run comparative tests.
The long delivery time is a pain.
E

Add an heat sink to the 5V regulator.

 

It could be becuase I have used a brand new breadboard that I have borrowed from my friend. Is it normal for 7805 to get very very got? I would be scared to leave my system running in case it catches fire

 

hi,
The wattage across the 7805 is the voltage drop across the 7805 times the current , so at 20V and 300mA.
15V * 0.3 = 4.5Watts, you must have a good heat sink.
For15V at 100mA , thats 10V *0.1A = 1Watt, the 7805 at 20C ambient is limited to approx 2Watts without an heat sink.
E

 

Hmm. Would you suggest using buck converter instead 7805 instead?

 

You could use a SMPS Buck Converter , its more efficient.
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=20V+to+5V+convertor&_sacat=0

 

Hello. I am working on my project and I need to measure solar panel current. I am able to measure voltage of the solar panel by using potential divider and connecting to analog pin of the arduino and then reading the pin. I also need to measure a current up to 1A and I have found a chip INA219. But i do not know how to properly connect this chip to my system. https://www.adafruit.com/product/904
I want to connect the current sensor to the positive terminal of my solar panel ( high side ) and display the current and voltage readings on my LCD display. Could someone give me some tips? Thanks

MOD: Rotated your image.
View attachment 164227

please if you know how to connect INA219 to the solar panel share with me
thanks

 

please if you know how to connect INA219 to the solar panel share with me
thanks

Could you give a little bit more details about how are you trying to connect things?



Looking at a basic INA219 example above, connect the positive terminal of your solar panel to Vin+ of INA219. Vin- of INA219 is going to your load (whatever you are trying to power off solar panel (battery charger or your load).