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Author Topic: Wire in external power and still control power?  (Read 329 times)
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I don't know if this is feasible, but I have a very small 40mm fan which is rated at 12 V/0.07 A, and the Arduino really can't run it with 5 volts. I plugged it into a 9 volt battery and the power worked great.

How would I go about adding around 9 volts for the fan while still letting the board control the power (this is a temperature control system for my BBQ smoker with thermistors. )


Thanks
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I don't know if this is feasible, but I have a very small 40mm fan which is rated at 12 V/0.07 A, and the Arduino really can't run it with 5 volts.
You need to look at voltage and current.  The fan needs 70mA at 12V. 

You'll need to use a transistor to connect it to an Arduino.  Some how I suspect others have done this.  (https://www.google.com/search?q=control+12v+fan+with+arduino)

I plugged it into a 9 volt battery and the power worked great.
FYI.  Those small 9V batteries are lousy at running motors (like fans).  It'll only last 4 or 5 hours if the fan draws 50mA (de-rating since you aren't running at 12V).  You'll want to use a AC to DC 9V supply.
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You'll want to use a AC to DC 9V supply.

My late father-in-law often mentioned a steam driven bbq spit design that he saw decades ago in a magazine (PM or similar I suppose). Alas he could never produce the design but was adamant that he had seen it, probably back in the 50s or so.

Since this is for a bbq, you could rig some kind of steam powered generator with the boiler tubes in the coals.....
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