Go Down

Topic: Power Supply For Arduino (Read 595 times) previous topic - next topic

NobleNoob

hmm, ok, well reverse is what cause both of my auto accidents lol...

could you tell me what kind of diode I need?

And....

How to wire it up?

I am so sorry to be a noob, but I am so happy cause you guys ROCK SO HARD!

I love the idea of using the 5V rail off the ATX supply for the arduino, cooler is better :)




CrossRoads

http://www.ti.com/lit/ds/symlink/lm1117-n.pdf

See section 4. 1N4002 from 5V to Vin.

Has been discussed in the forum as well.

Another manufacturer's data sheet went into it further. 
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

retrolefty


http://www.ti.com/lit/ds/symlink/lm1117-n.pdf

See section 4. 1N4002 from 5V to Vin.

Has been discussed in the forum as well.

Another manufacturer's data sheet went into it further. 


Another valid argument against powering an arduino via it's shield 5V pin is that because there is no Vin voltage being applied the auto-voltage selector circuit will be gating the USB's +5vdc voltage source onto the board's Vcc bus anytime you plug in the USB cable to the PC. This effectively means your external regulated +5vdc voltage source will be 'hardwired' to your PC's USB +5vdc voltage source. As those two voltages will never be exactly the same value at all times that can allow 'reverse currents' to flow where it was never designed to and can effect the both regulators feedback circuit. It's just not a good engineering practice to wire too different voltage sources together without proper isolation between the two sources.

But of course people have been powering their boards with external regulated +5vdc voltage sources via the arduino 5V pin and using the USB connection without experiencing any problems, so it's really a personal choice and will most likely never result in the burning down of one's home.  ;)
Lefty

Go Up