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Topic: more power (Read 7998 times) previous topic - next topic

tim845

Hey I have been making a setup to run an assortment of LED systems from my Arduino Mega.  

The problem is when I use the sample LEDs that I bought to get the programming done it works,  the the actual lights that I am wanting to run with the program need 12v of power.

how do you get 12v of power sent when the arduino only sends 5v?

Maybe its a stupid question, but that is my problem.

thanks for all your help.

ill_switch

Use a dedicated 12v power source (battery, wall wart, whatever) and connect it's GND to the Arduino's GND.

Alternatively, use one 12v wall wart to power the Arduino (via the DC jack) and use the "Vin" pin on the Arduino, which will then have 12v on it, to power your lights.

retrolefty

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how do you get 12v of power sent when the arduino only sends 5v?


That usually requires an additional external DC power supply rated at the voltage and maximum current required of all the loads using that voltage. The Arduino can then turn on and off various devices using either switching transistors or IC driver chips to 'isolate' the higher then +5v devices from the Arduino. The external power supply and the Arduino must have a common ground connection wire made between them. There are a ton of examples posted around here and on the Arduino web site showing how to wire up and control higher voltage/current devices to an Arduino.

Lefty


Senso

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Alternatively, use one 12v wall wart to power the Arduino (via the DC jack) and use the "Vin" pin on the Arduino, which will then have 12v on it, to power your lights.

The vin expects some nice and clean 5v, put it 12v and you have a fried arduino.

zorka

#4
Aug 05, 2010, 11:50 pm Last Edit: Aug 05, 2010, 11:52 pm by zorka Reason: 1
Quote
The vin expects some nice and clean 5v, put it 12v and you have a fried arduino.


From the hardware pages

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The power pins are as follows:

   * VIN. The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.

   * 5V. The regulated power supply used to power the microcontroller and other components on the board. This can come either from VIN via an on-board regulator, or be supplied by USB or another regulated 5V supply.

   * 3V3. A 3.3 volt supply generated by the on-board FTDI chip. Maximum current draw is 50 mA.

   * GND. Ground pins.


one of them must be wrong .....

retrolefty

#5
Aug 06, 2010, 12:24 am Last Edit: Aug 06, 2010, 12:25 am by retrolefty Reason: 1
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The vin expects some nice and clean 5v, put it 12v and you have a fried arduino.


Simply incorrect. Vin is usually in a range of 7.5 to 12vdc. Vin can be used to supply voltage to the Arduino, or if a DC power source is connected via the external power connector, Vin can be used to supply power to external components.

http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf

Lefty

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