5V, 240ma Fan

[Used]

I have a rasberry pi 3 B and i would like to plug my 5V , 240ma fan. How should I plug my fan and since the recommanded max current from a pin is 0.16a ?

[tweak42]

I have a rasberry pi 3 B and i would like to plug my 5V , 240ma fan. How should I plug my fan and since the recommanded max current from a pin is 0.16a ?

A quick search around and I cannot find where 160ma is the stated recommended max drawing from the GPIO 5v rail.

https://www.raspberrypi.org/help/faqs/#power
http://elinux.org/index.php?title=RPi_L ... Power_pins
Reading the documentation, it appears the actual max varies based on what else you have connected to your Pi 3, the quality of your USB power cable and the rating of the power supply you are using.

Thus a 240ma fan should work fine if you don't connect anything to the usb ports. Disabling or omitting connecting ethernet, hdmi, bluetooth and wifi could also save some power. If you need a usb device, you'll need to carefully test to see what works to avoid the lower power lightning bolt.

Or, you could just use a separate 5v power supply for your fan.

[Notilix]

I think you're a little bit confused ; I'll try to provide you some clarifications.


The RPi 3's header is composed of three types of pin. There are communication pins (these are GPIO), 5V pins (what you describe) and 3.3V pins.

About GPIO pins, used to communicate with other devices, you shouldn't draw more than 0.016A (16mA). You were right to check the limitation, you just forgot a 0.

As tweak42 said in his post above me, the 5V (and 3.3V) pins are not concerned about 16mA limitation.

[james-at-lo-tech]

3V3 current is very limited on earlier RPi due to the on board regulator.

[brekee12]

Simple use a TIP120 type transistor in open collector mode. This can drive even a 1A fun from 5V supply, loading raspberry output with a mA. 5V can be loaded with 240 mA only the power supply must support at least 2.5A-s to make sure raspberry gets enough power.

[mahjongg]

It depends on whether you want to control the fan or not.
You cannot power the Fan directly from a GPIO pin, as it can provide only 16mA max (not 160mA), the 5V pin however is directly connected to the 5V supply, and its current is only limited by the Power Supply, and the PI's polyfuse.
If you don not want to control the fan (why would you need that?) you can directly put it on the 5V pin, which normally can supply an extra 320mA on top of what the PI, and USB devices use.

[boyoh]

I have a rasberry pi 3 B and i would like to plug my 5V , 240ma fan. How should I plug my fan and since the recommanded max current from a pin is 0.16a ?

Just a Idea for controlling a 5v fan on the Pi .Using only the 5v rail
Using a transistor, withe the base switched by a Thermistor and
Trimmer, To run fan continua's but a switch across the thermistor

5+----------( fan )--------------------------- (c Transistor e )-----------0v-
5+-----( Thermistor)-----( Trimmer )----------( b )
---------( Switch )

Connect switch across Thermistor
Make shour trimmer go se no lower than 440r
Do research for Thermistor type