Connection of fan 5v to arduino

Projects General Guidance
1

Hi Guys, I have question about a project which is i use arduino UNO R3 and i use 2 fans 5v with current 0.24A each but they never work together they work each one alone and i use the connection like this image:
NPNMot-2.png

Also i have attached HC05 BT and MQ135. the power supply is 9v. I dont know if my approach can cause any damage or any danger with specs/peripherals i mentioned above attached to the uno or it is safe? as i will leave this project on for very long periods if not years so i wanted to make sure. Noticing that i had this on and its working flawlessly with no problem under my supervision for more than 12 hours x 4 days but i wanted to make sure and take experts opinion as well.

thanks

2

Is that 5V supply from a separate power supply?

3

Nope all supplied from the arduino

4

Not a good idea. Arduino can't provide that much current. Get something else to power the fan.

5

Is there any other way to make things safe but still without external power supply because supplies are not available nowadays

6

No. The Arduino will be overloaded and hot if you run it that way. Likely to reduce its life too. Look around - most people have a bunch of old phone chargers and the like that were never scrapped. See if you can find one that can provide the power you need.

7

Ok one more thing if i use the connections above in image can i provide the 5v and ground from external power supply while controlling it with arduino notcing that arduino is being power from different power supply than fans? or they all should use same power supply?

8

Separate power supplies are fine. Connect the grounds.