Hot answers tagged

24

It doesn't matter. Either way you are moving air one place to the other. Cooling is about volume of air, not the direction of travel. In theory, pulling air out may create negative pressure inside the case which, in theory, may be advantageous to cooling, however, in reality this is not going to happen unless your fan is a jet engine, which will probably ...


10

More information on this will be available as and when the units start arriving with purchasers and we get a clearer picture of overclocking capabilities and such. To the best of my knowledge the figures from the benchmarking done by the pimoroni.com blog are accurate: In terms of CPU temperature, the Raspberry Pi 3 runs significantly hotter than the Pi ...


6

It is simple to control a small fan with the Pi GPIO. I use a simple transistor circuit (with only 3 inexpensive components). I use the Pi 5V pin to power my fan, but this could be used with an external 12V supply for 12V fans. This is suitable for fans which draw up to 500mA. Substitution of a power transistor could be used to power larger fans. simulate ...


5

Yes, as the temperature rises the CPU frequency is lowered to prevent damage. The throttling begins around 82 degree Celsius. You can check the CPU Frequency with the following command: cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq or using the GUI widget. The following links provide additional info and benchmarks: http://www.sbeddoes.com/...


5

from gpiozero import LED #we are using the LED sub-module just as a generic output fan = LED(18) #for the positive, put the negative in one of the grounds def cputemp(): f = open("/sys/class/thermal/thermal_zone0/temp") CPUTemp = f.read() f.close() StringToOutput= str(int(CPUTemp)/1000) while True: cputemp() if StringToOutput >= ...


4

There are people who have watercooled the pi, I believe mostly as a novelty since doing this will cost more than it could possibly be worth. If you want something simpler, you could saw down a piece of heatsink, or ask at a computer store for something similar -- I recently got a B+ with an accessory package that (bizarrely) included aluminum sinks for the ...


4

At a PWM frequency of a nominal 10 Hz I'm not surprised you can hear clicks. You will be switching the fan on and off 10 times a second. Experiment with frequencies in the range 100 to 1000 Hz.


4

gpiozero has a CPUTemperature class allowing you to easily control devices based on the Pi's running temperature. And you should just use OutputDevice to control the fan: from gpiozero import OutputDevice, CPUTemperature fan = OutputDevice(18) cpu = CPUTemperature() while True: if cpu.temperature > 45: fan.on() else: fan.off()


4

Using PWM and a NPN transistor Let me begin by saying I'm not an electrical engineer. If someone who knows more sees a problem with what I present, please do comment! I found an excellent write-up for doing this with an Arduino here. I too, however, am using a RaspberryPi (RPi3). One concern that I've seen pointed out is that pulling power from GPIO18 to ...


4

The short answer is yes. The long answer is yes, but... 3.3VDC is enough to run a low speed fan provided its designed for 3.3VDC. I wouldn't try anything larger than a 40mm fan like this one, and this is why: the larger the fan blades are, the more torque is required to turn them, in in turn requires more power. When you only have 3.3 volts, it takes ...


4

You need to checkout this tutorial that covers controlling a DC motor using a Raspberry Pi. The Pi's GPIO pins are for very low current applications such as controlling a transistor or controlling an LED (with resistor). Here's quote from the tutorial: IMPORTANT: Do not connect a motor, no matter how small directly to the Raspberry Pi, it will damage ...


4

The fan is not connected to the GPIO. The GPIO are 3V3 and only supply a few tens of milliamps of current. The fan is connected to the 5V and ground rail. You will need to add circuitry to switch the fan on and off. The simplest is probably to add a transistor. The transistor would sit between the 5V supply and the fan. A GPIO could then be used to ...


3

You can power a small 5v fan off the 5V and the GND pins on Raspberry's GPIO pins. Check the GPIO layout HERE. I use this Kit and use pin 2 and 6. Hope this helps


3

You don't need any cooling for normal Pi usage. If the Pi is in danger of overheating it will throttle back the CPU to cool down. If you plan and need to run the Pi at maximum speed continuously then cooling will be useful. Cooling will lessen the need to throttle the CPU because of overheating.


3

Check that your fan works properly when plugged directly into 5V, and also if you set your PWM cycle to 100%. If it works when you plug it in directly, it might be that your motor doesn't like being driven with PWM. Many fans operate on a brushless DC motor, which incorporate some electronics to control the motor's stator coils. PWM switches the power on ...


3

STOP! You musn't ever connect a motor (fan etc) directly to a GPIO pin. Your fan works fine now as its basically connected directly to the 5V supply which is fine. The controllable GPIO pins on a Pi basically Don't have enough current to make a fan turn very well BUT MORE IMPORTANTLY Will almost certainly cause the Pin to stop working as a motor (fan) ...


3

I'd use a PID algorithm..And change the PWM duty cycle of the fan. Blog post using a PID loop to control a fan in python. The post used a add-on board but his weather_pwm code is the same as the GPIO.pwm library that comes with raspbian.For example of his PID python code HERE from github. The links to the PID source and a video example are in the blog post ...


3

The RPi is unlikely to be a problem. However if you insulate it well enough it will of course overheat eventually. There will be a temperature gradient from the RPi to the out of the outside of you r Plushie.


3

According to the official pin diagram, pin 2 and 4 are both 5v. Try to connect with pin 2 (5v) and pin 6 (ground).


3

A mis-placement of a heatsink of 1/2 mm will cause no trouble and no significant change in thermal behaviour. The only potential issue could be a damage and/or short circuiting of neighbouring components, e.g. R82 or R10. Those resistors are pretty close to the chip. Check those in detail - though from pictures of the PCB I would assume that you're pretty ...


3

Liquid cooling comes to mind as an alternative to heat pipes. There is a project called The Wet Pi: The Wet Pi is a fully functional water cooled Raspberry Pi, fitted with a micro pump, water block and reservoir. It is attached to the BCM CPU/GPU, the Ethernet/USB controller, and the power regulator, as these are the components that generate the most ...


3

GPIO pins 4 (+5v) and 6 (GND). I peeled back the two leads from a GPIO-to-breadboard ribbon cable and soldered to two female-ended breadboard cable leads and connected them to the GPIO pins. Pi 3B/Ubuntu Ma'te desktop.


3

I would lean toward providing some ventilation in a case for the RPi 3B+, especially if it will be used as a media server. Heat will not only reduce the life of electronic components such as your CPU/GPU, it may also affect the life and reliability of your SD card. There are a variety of opinions on this question, but I figure it this way: ventilation is ...


3

Ventilation is a good idea if you notice the core temperature getting much above 60-65 °C. vcgencmd measure_temp ...Will tell you this. Note that throttling will kick in if you get close to the recommended maximum; I think it starts upwards of 80 °C, the maximum being 85. You want to prevent that from happening. most of the cases I am finding don't ...


3

I think the IRLZ44N transistor is extreme overkill for the fan you're using. The blog you've quoted is lacking in important hardware details (I've not read his code), but it appears he's just ON-OFF banging a 2-wire fan with a GPIO pin driving a MOSFET. I'd counsel some caution in following the approach outlined here, but I may be a bit biased by people who ...


3

For Fans with integrated PWM controllers Good practice is to install a single series resistor (50-100Ohm) to limit the current in case of accidental short circuit or failure of the fan. No additional hardware is necessary, and if you can tollerate that risk it will be fine for reasonable <1M long GPIO cables without a series resistor. Note that some ...


3

You've not told us which RPi you are using. For example, a Pi Zero consumes less power, and generates less heat than the RPi4B. That will matter quite a lot when you get to the detailed design stage; when you need to determine what your objective Junction Temperature is, and how much cooling you need to meet that objective. Are Heat Pipes a Solution? If ...


3

Your question should be "Which material has a lower thermal resistance: thermal paste, or thermal pads"? The material with the lower thermal resistance will keep the temperature of your components coolest for any given heat sink. To find the answer to your question, we should do an Internet search. This search yields a link that contains the answer to your ...


3

That will depend on things that you've not told us. But not to worry, because we'd have a hard time answering your question with any authority even if you had! That sounds nonsensical, but here's what we know, and why a definitive answer is difficult: The RPi 4 has what you might think of as a closed-loop thermal management system that is "baked in&...


3

You can typically simply connect the PWM input to a GPIO providing a 25kHz PWM signal. I don't agree with the other answers, which all mention to keep Vcc within the logic level of the Pi, which from my experience is not neccessary! Fan controllers in 4-pin fans have an open collector input for PWM control and thus are made to be controlled by typical logic ...


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