Hey guys, I am new to these forums and the arduino products in general so please excuse my noobish question.
here it is: Is it possible to regulate the mA and the voltage that comes out of the 5v out pin on the Uno r3?
Any help would be greatly appreciated!
Thanks!
Anything is possible given enough information.
Tell us what you want to do in DETAIL.
You will not get answer that is meaningful unless you give the information.
There are just too many variables in your questions!
Weedpharma
First, you can't "pull" much power out of that pin.
It gets complicated when you try to figure-out how much power you can get-out, it depends on the voltage applied in front of the voltage regulator and how much current you are "pulling" out of the ATmega chip, etc.
That pin is good if you want to power an LED or two, or if you need a 5V "reference voltage" with almost no current. If you want to do more than that... it gets complicated.
Is it possible to regulate the mA and the voltage that comes out of the 5v out pin on the Uno r3?
You can "regulate-down" if for example you need 3.3V for something. It's possible to boost the voltage, but you'll get even less current.
Normally, you don't "regulate" current (mA). The relationship between voltage, resistance, and current is defined by [u]Ohm's Law[/u]. Most of the time the voltage is constant and the amount of current is determined by the load resistance (or impedance).
If you "try" to get too much current out of a power supply (or out of anything) the voltage will drop, and bad things might happen. For example, if you live in the U.S., the voltage at your power outlet is 120VAC.
That wall-voltage is present whether anything is plugged-in or not. If you plug-in a 100W light bulb, about 1 Amp of current flows. Plug-in a 2nd lamp and twice the current flows. Plug-in enough light bulbs or 2 or 3 toasters, too much current flows and you blow a circuit breaker.
The 5V pin is already regulated, at 5 volts. You can regulate the Current (mA) by adjusting the resistance of the load attached. Ohms Law tells us that the V=IR or in the case of selecting for the current I=V/R...
So supposing you want to draw 20mA off of the 5 volt pin, 20mA=5/R, R=250Ω...
Not so much a noob ish question but a none question. As stated it simply does not make any sense. You can add things to make the voltage less or more. What you add will define what current you have taken from the pin.
The current will only be that determined by the resistance of what you connect to the pin. Beginners often ask things like " if I connect a 2 Amp power supply to the arduino will it blow it up as it only needs 0.030 Amps?". The answer is that the 2Amps is only what the power supply can provide not what it will force through the circuit.
5V pin will only provide up to 800mA less whatever the board is using, and more likely much less as the 5V linear regulator heats up and goes into thermal shutdown. You may get somewhat close with 7.5V in, and much less with 9V or 12V.
If you need a lot of 5V current, use a separate switching regulator wallwart.
http://www.dipmicro.com/store/DCA-0520
http://www.mpja.com/5-Volt-DC-Plug-Power-Supply-4A-Regulated/productinfo/18520%20PS/
Is it possible to regulate the mA and the voltage that comes out of the 5v out pin on the Uno r3?
google Ohm's Law