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MegaWatt vs. Chinese Imitation 30 amp switching power supply comparison
- Thread starter Moleculo
- Start date
Been using them for a few years now and I added a large 4M cap as a filter and no problems. I got it from a auto stereo shop.
The fans run all the time to eliminate heat cycling. The constant heating and cooling of the internal parts of a power supply is what causes early failure. The problem is the power supply needs 25 CFM to keep it cool so the movement of air is what you are hearing. The fan manufacturer and my db meter both read 30 db at 3 feet with the fan blowing away from the meter. Feel free to open the case and change the fan if you can find one quieter but 30 db is the quietest double ball bearing fan I can find that moves 25 CFM. I know this thread is old but I didn't see it before.
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Fan doesn't bother me at all
Tells me it's working........ working great for 5 years and counting now.
Yes, some people are super sensitive to noise. 30 db is equal to leave rustling sound-wise. I have a video of four S-700-12 power supplies running in parallel on my website. Its a great way to compare my voice to the sound of four units running together before you buy. One power supply is a lot quitter than four running together too. If anybody knows of a 60mm X 60mm X 25mm 12 volt 25 CFM fan than is quieter than 30 db please tell me about it.
I have a ham friend that just bought one, and he seems really happy with it.
73,
Brett
Feel free to change the fan without voiding the warranty. The only thing I ask is to give me the make and model number of this 25 CFM quite fan so I can use it. The only way I have found to make it quitter is to install less CFM fans. This will increase heat and reduce life.
Did you change vendors of your fans since I bought mine way back? The fan RPM's might be what is causing it to be objectionable to some. I have my 50 amp unit sitting on a cookie sheet in the area where I charge and discharge my Drone Batteries. I don't really need that much power for the batteries except when I am charging 5 batteries at a time. It is hard to believe that thing can fly with batteries that big and heavy.
No vendor change, we just went to double ball bearing fans. The problem is if you reduce RPM you reduce CFM and cooling. To some its not loud if placed away from the radios and mics. To others its a jet engine. To me its not that loud as you can here four running in the 200 amp video. The server power supplies are about three times as loud. If anybody knows of a quieter fan???? Its really just the air blowing through the case that you here. We opened up the front of the case a few months ago, on our latest model, to let the air flow out with less restriction. That helped some.
Thanks, but I sold it on Monday and it went to USPS yesterday and is on its way to its new home.
I keep it quiet enough in the shack that I can easily hear the hum of the RS-50M under the desk. I have it supported off the floor which reduced its noise considerably and I can still hear it quite well.
If the fan in the Megawatt 50 had been under thermal control--as I incorrectly assumed it would be--it's quite likely I would still have it. But having that fan running full tilt even with no load was a deal breaker for me.