How to disable fan noisy Meanwell MP650

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I own a Meanwell MP650 2J2J8 SMPS power supply. Unfortunately is has a fan build in that is very noisy. The fan is secured: when I disconnect it the power supply doesn't work. I think with normal small (music) loads the power supply doesn't need the fan to keep it cool. I extended the wires of the fan and build it in a small case that keeps the noise inside, but this is not a final solution. Any ideas how to disable the fan and keep the power supply working?
 
The obvious question I have is why did you get such a powerful supply. Do you actually listen the music at 650 watt. I have a fair sized lounge which is 11 x 15 x 3 meters and I use a JLH 10 watt per channel class A amp at a moderate setting and enjoy quite pleasant music levels.

The power supply you bought is for 650 watt continuous and a safety fan is built in it for this purpose. If the fan stops working the power supply will stop and is a safety design feature If you are not using 650 watt then you should have bought a 50 watt power supply instead which have no fan.

Sometimes buying something for bragging rights defeats the object totally. That said if you listened to music at 650 watt then you would not hear the fan.
Design the equipment for the purpose and you will not run into such silly problems.
 
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Hello.
I own a Meanwell MP650 2J2J8 SMPS power supply. Unfortunately is has a fan build in that is very noisy. The fan is secured: when I disconnect it the power supply doesn't work. I think with normal small (music) loads the power supply doesn't need the fan to keep it cool. I extended the wires of the fan and build it in a small case that keeps the noise inside, but this is not a final solution. Any ideas how to disable the fan and keep the power supply working?
What is the voltage of FAN ?
Can you provide a very good photo of PCB (recto verso)?
Take informations write on any IC.
 
I am 35 years beyond my disco going age - let alone running a noise generator for gyrating kids.:)
Maybe I would go to a high end strip club now and then, but even then you pay more attention to the lap dance that the crappy overbearing music.

That's shows a distinct misunderstanding of discos.
I often play to older crowds in pubs.
I am more retro than modern.
 
Hello.

What is the voltage of FAN ?
Can you provide a very good photo of PCB (recto verso)?
Take informations write on any IC.
Do you think you have a workaround for this if I give you the information? What exactly do you mean with PCB, the fan?

I buyed this power supply together with three second hand Hypex UCD 400 OEM. Two of them played well with this power supply, until I I decided to buy a hypex SMPS. But now I do some experiments with other class D amplifiers and I could use the Meanwell very well.
 
What exactly do you mean with PCB, the fan?

Not the FAN,this is photo of PCB

components.jpg
 
If the psu will not work without the fan, then the psu has a sense wire in addition to the fan power. Are there three wires to the fan?

Some fans have a pulse output that give an indication of rotor speed. Computer BIOS can display fan speed in some utility that some PCs have.

Usually, for industrial fans, a "stuck rotor" signal is all that is required. If the fan is seized, then a signal line is pulled high, so the monitoring circuit knows that there is a problem.

If the signal line is connected to the -ve fan connection, then it mimics the open-collector "fan ok" signal from the fan. It should run ok, but the protection is now disabled.
 
That's shows a distinct misunderstanding of discos.
I often play to older crowds in pubs.
I am more retro than modern.

When you mention disco, all I remember bell bottom jeans, long pointed collar and cuffed shirts plenty of coloured drinks, many Bose 901's, racks of Phase Linear's and motown. Donna Summer, Gloria Gaynor, The Supremes, Temptations, Gloria Gaynor, MFSB, Love unlimited, Van Mcoy, Golden Earing.....
 
Meanwell included the fan sensing for safety reasons. Taking out the fan is the same as de-rating the PSU\. In that case you may as well replace it with a 100 watt PSU without a fan.

If you do what theAnonymous1 suggests then I would suggest to include a temperature sensing circuit that will control the fan speed automatically. This is not too difficult to do and won't have to worry about hearing the fan when playing at moderate levels.
 
If the psu will not work without the fan, then the psu has a sense wire in addition to the fan power. Are there three wires to the fan?

Some fans have a pulse output that give an indication of rotor speed. Computer BIOS can display fan speed in some utility that some PCs have.

Usually, for industrial fans, a "stuck rotor" signal is all that is required. If the fan is seized, then a signal line is pulled high, so the monitoring circuit knows that there is a problem.

If the signal line is connected to the -ve fan connection, then it mimics the open-collector "fan ok" signal from the fan. It should run ok, but the protection is now disabled.
Indeed three wires to the fan. If I block the rotation of the fan the psu stops working. I have tried connecting the wires but didn't succeeded.

For home use the power consumption is very low. I've played for months with the fan in a separate box without any heating problems so I am not afraid of heating problems.
 
I had a similar problem when I used a big 750 watt SMPS. It's fan came on full blast when powered up.

This drove me completely insane because it was very loud and made this PSU very unsuitable for audio until your thread here, which made me think....

It is a 3-wire fan and the third wire is used for sensing the fan run/not run. I had a look if this could be circumvented and found that injecting a square wave into that point tricked the PSU into thinking the fan was operating.

I generated a square wave from my sound card at about 100Hz via a 10K resistor into the test pin and the PSU fired up without the fan connected.

Although I would not suggest that you run the PSU under full load without a fan, this could be an interim solution to reduce the annoyance.
 

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I had a similar problem when I used a big 750 watt SMPS. It's fan came on full blast when powered up.

This drove me completely insane because it was very loud and made this PSU very unsuitable for audio until your thread here, which made me think....

It is a 3-wire fan and the third wire is used for sensing the fan run/not run. I had a look if this could be circumvented and found that injecting a square wave into that point tricked the PSU into thinking the fan was operating.

I generated a square wave from my sound card at about 100Hz via a 10K resistor into the test pin and the PSU fired up without the fan connected.

Although I would not suggest that you run the PSU under full load without a fan, this could be an interim solution to reduce the annoyance.
Thanks for this contribution! I tested some things but just connecting one of the wires to the sensing one is not enough. The signal must have a pattern. Any ideas for generating a signal without a soundcard? I'm thinking of using the mains frequency?

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Thanks for this contribution! I tested some things but just connecting one of the wires to the sensing one is not enough. The signal must have a pattern. Any ideas for generating a signal without a soundcard? I'm thinking of using the mains frequency?

You can buy silent or virtually silent fans.

I would be careful messing with mains especially as the power to the SMPS is full wave rectified from the mains so isn't relative to neutral line.
 
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