开云体育

  1. BITX20
  2. Topics

Cooling RPi4 in Sbitx

 


The question whether the RPi4 should be installed without cooling or with cooling does not let us rest.
I looked through several test descriptions, where they show measurements depending on the number of processors /
CPU frequency used and with different cooling solutions.
The point is that there can be a difference of up to 30 degrees C with or without the refrigerator.
In the state without a cooler, 85-88 degrees Celsius is also possible.
While the most effective passive cooling is 50-63 degrees Celsius.
Since I used an RPi400 so far, I have no experience, but I think that some kind of cooling is necessary.
(I don't mean the 3 small cooling surfaces)
I'd like to hear other people's opinions and experiences.
--
Gyula HA3HZ
 

My radio has been running continuously for the last one week, this is our peak summer, with temperatures soaring to 38 c. The shack's air conditioner is in on only about 3 hours day.
It has run without problem.
- f

On Sat, Apr 15, 2023, 6:07 PM HA3HZ <gyula@...> wrote:

The question whether the RPi4 should be installed without cooling or with cooling does not let us rest.
I looked through several test descriptions, where they show measurements depending on the number of processors /
CPU frequency used and with different cooling solutions.
The point is that there can be a difference of up to 30 degrees C with or without the refrigerator.
In the state without a cooler, 85-88 degrees Celsius is also possible.
While the most effective passive cooling is 50-63 degrees Celsius.
Since I used an RPi400 so far, I have no experience, but I think that some kind of cooling is necessary.
(I don't mean the 3 small cooling surfaces)
I'd like to hear other people's opinions and experiences.
--
Gyula HA3HZ

 

Gyula

many of us, B26-RF2K-S amplifier users, is using passive heatsink from this link on Pi4:

On the other hand, as Farhan tested, it looks like it is not needed. (and not sure if it would fit in new slim case)

- P
 

I thought exactly that the new house might not fit any cooling surface.
Although I found a 7mm high heatsink that might still fit... the question is whether it is really necessary.
I'll post a picture:
--
Gyula HA3HZ
 

I know that the testing is done with programs that use the CPU.
It can also be called an overload test.
In our case, the goal may be to avoid heat production due to long-term use.
The question is whether the center cooling surface does as much cooling as opposed to letting the air flow.
--
Gyula HA3HZ
 

开云体育

I think the biggest impact of getting devices to be cooler is the change in lifetime. ? An individual semiconductor device has a lifetime measured in many many many years. ? But it’s a strong inverse relationship to temperature. ?

And the problem may be that we have a bunch of semi connectors in complicated systems ? ?Because the failure of a complicated device with 1 million semi conductors could be the combined risk of ANY of the 1 million failing then the chance of total device failure could be as much as 10 to the sixth greater than the risk of one failure. ?(In practice I bet you could live with an I/O ?that quit working however. but it might require both hardware and software changes to keep working)

Here’s a plot that shows how strongly it’s related to temperature for a single example device ?


image0.png

After looking at that plot it looks like the risk to individual analog transistors is much smaller than the risk to complicated integrated circuits or processors. ? ? The article explains that in order to get meantime between failure manufacturers use elevated temperatures because otherwise indivisible semiconductor devices are just unlikely to fail before their useful marketing of sales is over— so they wouldn’t be able to even finish testing before the device had been superseded

So getting the temperature down by 10 or 20°C might be worth it if you want the thing to keep working flawlessly for a long time. ? If your interest is much shorter lived then it might not be worth it

Gordon Kx4z





On Apr 15, 2023, at 11:52, HA3HZ <gyula@...> wrote:

?I know that the testing is done with programs that use the CPU.
It can also be called an overload test.
In our case, the goal may be to avoid heat production due to long-term use.
The question is whether the center cooling surface does as much cooling as opposed to letting the air flow.
--
Gyula HA3HZ

Dan Eggers N7DE
 

开云体育

For most transistors the data sheet gives some suggested limitations on the operating temperatures.? I have a General IRT207 Infaraed Thermometer that will tell you what the temperature of a single point is, and they are relatively inexpensive.? They are made for measuring the temperatures of surfaces in buildings.? I am a believer in lots of heatsink area.? I tried to publish an article with infarred pictures in QST, but they decided not to publish my article.? ? ? ? 73, Dan Eggers, Radiotelegraph N7DE

From: [email protected] <[email protected]> on behalf of Ashhar Farhan <farhanbox@...>
Sent: Saturday, April 15, 2023 5:43 AM
To: [email protected] <[email protected]>
Subject: Re: [BITX20] Cooling RPi4 in Sbitx
?
My radio has been running continuously for the last one week, this is our peak summer, with temperatures soaring to 38 c. The shack's air conditioner is in on only about 3 hours day.
It has run without problem.
- f

On Sat, Apr 15, 2023, 6:07 PM HA3HZ <gyula@...> wrote:

The question whether the RPi4 should be installed without cooling or with cooling does not let us rest.
I looked through several test descriptions, where they show measurements depending on the number of processors /
CPU frequency used and with different cooling solutions.
The point is that there can be a difference of up to 30 degrees C with or without the refrigerator.
In the state without a cooler, 85-88 degrees Celsius is also possible.
While the most effective passive cooling is 50-63 degrees Celsius.
Since I used an RPi400 so far, I have no experience, but I think that some kind of cooling is necessary.
(I don't mean the 3 small cooling surfaces)
I'd like to hear other people's opinions and experiences.
--
Gyula HA3HZ

 

Cooling is up to you to figure out if you need it.

Most of my pi's are passive cooled but not in any enclosures that restrict air flow either.

The only two exceptions here are my Raspad 3 and the pi400 keyboard. The raspad 3 has a fan built-in since it is pretty restrictive on the air flow. The pi400 keyboard has enough cooling built in as not to worry about adding a fan.

From seeing the pictures of the case for the sbitx, I'd probably see about adding a fan because of all the other heat producing elements of the system. I have no idea how much heat all the other parts produce but better to side on caution.

James W8ISS
 

James, I agree with you.
Unfortunately, the construction makes it difficult for me to solve the cooling for several reasons.
The heat dissipation of the heatsink shown in the previous message is also unfortunate, because it would be between two mounted PCBs. Therefore, a fan might be a better solution due to free air flow. If you really need it. I accept that it is good to have cooling, so I am looking for a favorable option.
--
Gyula HA3HZ
 

开云体育

Again, I think this is more of an issue if you plan for this to run for hundreds of hours and many many years. ?

For instance, I run two Winlink radio message servers at my house and they have been running 24/7/365 for six years. ?

So it’s a trade-off whether it’s worth it to run air conditioning a little bit in that part of the house or just accept the fact that they may quit a few years earlier.?


On Apr 15, 2023, at 16:19, HA3HZ <gyula@...> wrote:

?James, I agree with you.
Unfortunately, the construction makes it difficult for me to solve the cooling for several reasons.
The heat dissipation of the heatsink shown in the previous message is also unfortunate, because it would be between two mounted PCBs. Therefore, a fan might be a better solution due to free air flow. If you really need it. I accept that it is good to have cooling, so I am looking for a favorable option.
--
Gyula HA3HZ

 

Yes …and even more, if Farhan did not find the reason for cooling it with additional
heatsink then I don’t care, right now.?

- P
 

The specific solution will probably be implemented during operation.
--
Gyula HA3HZ
 

On the sbitx v2, we have? ample air vents on the top of the raspberry pi as well as on the side panels.
I have busted tens of raspberry pi boards but none from too much heating.
The raspberry pi draws about 250 mA of current at 5 volts. That is, about 1.25 watts. This includes chips other than the CPU itself. The heat is not really an issue with the raspberry pi. The main issue is with thr driver and the power amp transistors.
- f

On Sun, Apr 16, 2023, 2:26 AM HA3HZ <gyula@...> wrote:
The specific solution will probably be implemented during operation.
--
Gyula HA3HZ

 

Thanks for the detailed information. I know that the solution is always in the details.
I noticed that the heat generating components are well placed on the SbitX v2 pcb.
It is still hard for me to realize that the device can be protected with control and clever technical solutions.
I've always been interested in the line from 'Minima' to 'SbitX'.
I especially like the All-In-One endeavor.
--
Gyula HA3HZ

1 - 14 of 14