Overheating Mecool M8s Pro L and Pro + (and others ?) - Options ???

[pégaso]

For Netflix 1080p and 1080p H264 / HEVC videos up to 20 Mbps is it necessary to replace the heatsink? If this is needed here (https://www.banggood.com/40-x-40-x-1...-p-914845.html) does it fit the Pro L without cutting off the top cover? Or would that copper be better (https://www.banggood.com/Raspberry-P...p-1045808.html )?

OBS: Translated into English by google translator.

[P.X]

That fan is rated 23dBA - probably their highest rated fan at those dimensions. They have ones that are rated half that.

Not sure where you are looking but I got switches from 35C to 50C - and they had ones with even lower temps. From Pierre Omidyar's site - this forum is ridiculous with the censorship.

Thanks. I was just looking at cheap ones on the UK Bay !

[jebivetar]

SUNON MC30100V1-000C-A99

Looking at the available options 40°C is the lowest available temp so that would probably be the one to choose - or maybe 45°C or .... Someone may have a better idea ...?

I would still use a resistor, but have the temp. switch to save fan life.

That fan is rated 23dBA - probably their highest rated fan at those dimensions. They have ones that are rated half that.

Not sure where you are looking but I got switches from 35C to 50C - and they had ones with even lower temps. From Pierre Omidyar's site - this forum is ridiculous with the censorship.

[P.X]

SUNON MC30100V1-000C-A99

Maglev Fan

....

Trouble with attaching little bi-metallic switch is choosing right one ??

CPU Temp is internal SOC temperature and you need surface temp of heatsink. Need to choose switch on Temp probably at least 20°C above idle temp so that the 15° On-Off spread is covered and the fan just doesn't stay on all the time. I think it probably requires real world testing with a number of values for On-Temp for switch KSD9700

EDIT:
Looking at the available options 40°C is the lowest available temp so that would probably be the one to choose - or maybe 45°C or .... Someone may have a better idea ...?

I would still use a resistor, but have the temp. switch to save fan life.

[P.X]

Simple method for selecting appropriate resistor value ...

Use the ratio of desired new to input voltage
e.g. 4/5th of input

Formula for R given ratio A/B (Vout : Vin)

R = (1/A)*Rfan * (B-A)

e.g. 4/5th Input Voltage
R = 1/4*Rfan * (5-4)
R = 1/4*Rfan

Personally I just draw a little ladder and just read off the required final ratio.

5/7th

-> 2/5th Rfan

[clarkss12]

Hi

I don't have one of these yet - I just ordered an L - but I did also grab some KSD9700 thermal switches with the idea of having it close the circuit with a fan somewhere 40-50c. Someone earlier in the thread wanted to know how to turn the fan off when he goes to sleep.

I have a pretty quiet off-brand Chinese 40mm 12v that I scavenged off of some ancient device, can't remember which, that will probably be used, although I'm looking at some Sunon MagLevs if I can find a proper specced one. Note not all MagLevs are the same and the dBa ratings can vary wildly model to model, even of same dimensions.

I'll probably be running the 40mm fan from USB 5V to the KSD9700 via XL6009 buck boost module at some near-silent voltage. It barely turns on at 5v.

There are probably more appropriate tiny boost modules around, I just happen to have a bunch of these. Likewise, if you don't want to mess around with diodes and ohms gives you headaches, there are also tiny MP1584 adjustable buck converters (for stepping down 5v to arbitrary lower voltages) available for like $3 for 5.

Maybe in the future I'll look into increasing voltage as the temperatures demand.

I highly doubt I'll be keeping the M8S in its enclosure - it's exceptionally ugly, the cooling issues notwithstanding - and will probably just put it on a bunch of nylon stand-offs or something.

The parts above are a buck or two a pop and googleable.

Another interesting option, thanks...... found one for $1.24 USD, normally open and closes at 45 C, so fan only comes on at 45 C. But no speed control with this switch.

Edit: With my fan mod, when running idle, the temp is less than 45 C, so with this switch, the fan would not be running. However, when i receive my resistor/diode and install them, not sure what my idle temp will be. I do prefer to leave my boxes running 24/7 but with my fan mod, the noise is too much of a nuisance, so I shut the box off when no in use.

[jebivetar]

Slight corrections to my previous post - I thought I ordered a Pro L, but I didn't actually order one.

Now I remember why I haven't bought anything from GearBest in a year - their system and service is unbelievably awful. My chosen shipping method is unavailable, they tell me after 3 days via supp;ort message, but don't actually provide available shipping method in the ticket. I open a support chat to try to get some clarification, I get asked if I want to cancel the order, which I decline, but the order is cancelled away and I see no money returned to PayPal. Quite awful.

My 30mm maglev is super noisy. I have reverted to the 30mm Pi fan(67Ohm) + 33 Ohm resistor. Total cost $1.40 or less.

The KSD9700 look good. You will have to post if you do any experimenting on an appropriate value for On Temp

Which model MagLev? Sunon probably manufactures thousand different models at any point in time.

I was planning on dipping the KSD9700 in some cheap Chinese thermal paste and placing it on top of the heatsink. I don't think I'll be using the original heatshink though - I have accumulated quite a collection and probably have something better that fits (old flat Pentium heatsinks come to mind).

[P.X]

Lots of food for thought there, thanks for all the interesting info.

My 30mm maglev is super noisy. I have reverted to the 30mm Pi fan(67Ohm) + 33 Ohm resistor. Total cost $1.40 or less.

The KSD9700 look good. You will have to post if you do any experimenting on an appropriate value for On Temp as the outer HS temp will be lower than the inner displayed SOC Temp I guess. Sounds like a better option than a thermistor set up.

The IC buck/boost options are very interesting. Let us know how you get on.
They were probably beyond my needs/wants.

[jebivetar]

Hi

I don't have one of these yet - I just ordered an L - but I did also grab some KSD9700 thermal switches with the idea of having it close the circuit with a fan somewhere 40-50c. Someone earlier in the thread wanted to know how to turn the fan off when he goes to sleep.

I have a pretty quiet off-brand Chinese 40mm 12v that I scavenged off of some ancient device, can't remember which, that will probably be used, although I'm looking at some Sunon MagLevs if I can find a proper specced one. Note not all MagLevs are the same and the dBa ratings can vary wildly model to model, even of same dimensions.

I'll probably be running the 40mm fan from USB 5V to the KSD9700 via XL6009 buck boost module at some near-silent voltage. It barely turns on at 5v.

There are probably more appropriate tiny boost modules around, I just happen to have a bunch of these. Likewise, if you don't want to mess around with diodes and ohms gives you headaches, there are also tiny MP1584 adjustable buck converters (for stepping down 5v to arbitrary lower voltages) available for like $3 for 5.

Maybe in the future I'll look into increasing voltage as the temperatures demand.

I highly doubt I'll be keeping the M8S in its enclosure - it's exceptionally ugly, the cooling issues notwithstanding - and will probably just put it on a bunch of nylon stand-offs or something.

The parts above are a buck or two a pop and googleable.

[P.X]

I just ordered this 1N4001 Diode - 10 pack PRODUCT ID: 755 $1.50. Somewhere on Freaktab, someone said they used a diode instead of a resistor, but can't remember who it was. Anyway, I was looking for a solution to control the fan based on temp, using a thermistor, but no luck so far. I did read where others used a diode to drop the voltage .7 volts, but does not decrease the current like a resistor. So, now I have both, resistors and diodes coming.

Both will decrease the current otherwise the fan would spin at the same rate.

A standard diode is quoted as having a forward bias voltage drop of 0.7V but it is slightly more complex than that. The voltage drop curve has a knee at 0.7V and you will probably see about that drop at the fan.
The other poster ended up using 2 diodes in series and is very happy with the results.

It may be easier to use diodes as the results will be fairly similar pretty independent of the particular fan resistance.
With a resistor in use you have to choose based on the desired voltage and fan resistance. You may be able to get a more exact speed with the resistor as you can choose smaller steps, but as found in actual use, one or two diodes in series may produce the desired result.

Let us know what you find ....

[clarkss12]

I just ordered this 1N4001 Diode - 10 pack PRODUCT ID: 755 $1.50. Somewhere on Freaktab, someone said they used a diode instead of a resistor, but can't remember who it was. Anyway, I was looking for a solution to control the fan based on temp, using a thermistor, but no luck so far. I did read where others used a diode to drop the voltage .7 volts, but does not decrease the current like a resistor. So, now I have both, resistors and diodes coming.

[P.X]

Thank you, what surprises me, my fan was almost silent while sitting ON my box, now it is LOUD........ Perhaps, since it is sitting pretty much on the heat sink, maybe it is obstructing the air flow causing the audible sound.

Yes, a bit noisier, but you can hear it at the start of the video when testing. I think the box is probably acting as an echo chamber and amplifying the sound. Also air flow is greater now it is going directly into the box ?? Difficult to guess exact cause, but a resistor will slow things down and help with the noise.

[P.X]

OFF Topic.
For your next / My latest - project (not a TV Box mod)

50" TV Stand with cantilever arm. 46" TV - Tested OK with 55" 22Kg

[clarkss12]

https://www.youtube.com/watch?v=OXx5Ri3TIwk

Viewer number 7.
Very good.
Blame P.X

That is the way I fitted my other fan in - fan pushed up from inside - and dragging air in is good (in my opinion.)

That is a hefty soldering iron, well done.

Thank you, what surprises me, my fan was almost silent while sitting ON my box, now it is LOUD........ Perhaps, since it is sitting pretty much on the heat sink, maybe it is obstructing the air flow causing the audible sound.

[P.X]

Crappy video posted......... What a job......... going to order resistor now.

https://www.youtube.com/watch?v=OXx5Ri3TIwk

Viewer number 7.
Very good.
Blame P.X

That is the way I fitted my other fan in - fan pushed up from inside - and dragging air in is good (in my opinion.)

That is a hefty soldering iron, well done.