Voltage measuring and Power Source With same Battery

I’m Started a project of 12v DC UPS.the Problem which i faced that when i’m using battery for powering Arduino nano and a circuit for measuring the voltage of same battery with this board.in result board is burned or damage.This is my Complete Circuit in Attachment.

If you are powering a Uno from a 12 volt battery, you should use the pin marked Vin, not the one marked 5V (as your diagram appears to show). This way, you ensure that the external power source goes through the UNO's on-board regulator.

Screenshot (134).png

6v6gt: If you are powering a Uno from a 12 volt battery, you should use the pin marked Vin, not the one marked 5V (as your diagram appears to show). This way, you ensure that the external power source goes through the UNO's on-board regulator.

There are many errors in that schematic but I don't think that's one of them. The Arduino appears to be powered via its 5V pin from the output of a 7805 regulator. Which should be OK, if some smoothing caps are added. Question is why not use the on-board regulator via the Vin pin (as you suggested)?

Hi,
The OPs circuit shows a 7805 reg then feeding 5V to 5V pin, so okay there.

But

  • Where are the capacitors that should be around the 7805 to keep it stable? Check the data sheet.
  • What are your relays, you cannot control them by the output of the UNO if the coil draws more than 40mA.
  • You also have no flyback diodes fitted.
  • You should be able to Export a jpg image of your circuit, rather than do a screen capture, the resolution will be much better.

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

Thanks… Tom… :slight_smile:

Yes, I spotted 1, 2 & 3 also, and a dozen others. Can't be bothered to type them on my smartphone, may have some pc time later.

Actually i'm not using 7805 for regulation. 1.m using LM2596 Adjustable Step Down DC To DC Buck Converter. 2.For relays operation m using 2 channel 5V Relay Module. 3.and I don't Know about the exact use of fly-back diodes.

Hi,

Can I make a suggestion, forget the CAD and please post a copy of your circuit, a picture of a hand drawn circuit in jpg, png?

That way you can draw the proper components and label the pinouts.

Thanks.. Tom... :)

Assuming the CCM and R1(2) inputs are 5v, The most obvious error is the 3 diodes do not have any current limiting resistor.

JR

JohnRob:
Assuming the CCM and R1(2) inputs are 5v, The most obvious error is the 3 diodes do not have any current limiting resistor.

If it is 5V, even red 1.8Vff leds won’t have enough voltage to light them. And they are driven by a relay?

What are R3, R4 and D4 intended to do?