Coil whine issues
Any suggestions on how to reduce coil whine? Glues and epoxy suggestions are welcome, but I want to try to reduce it on the software side too so that I can make the hardware solutions even more effective.
My pfsense system is a socket 754 laptop with a Turion ML-40 (k8 at 2.2 ghz,) an ati RS480M chipset, a socket 939 CPU heatspreader attached to the CPU with thermal paste on the CPU and super glue at the edges once it settled, a scythe ninja fanless CPU heatsink held on with zip ties, 512 mb ddr, a 4gb usb flash drive, an atheros mini pci wireless interface as OPT1 (labeled ath0) interface bridged to LAN, a relteak onboard interface as WAN interface (labeled rl0,) a USB NIC as LAN interface (labeled ue0,) and no fans connected.
I am having coil whine issues. The issue wasn't present in ubuntu x86.
I have had the same coil whine on pfsense 2.0.1 and 2.1 (i386 nanobsd_vga)
I'm not sure if it is just normal coil whine, or something else.
Can't you hide it in the attic? (or reduce the no. of USB devices attached)
Wouldn't be a very good idea. In the summertime the attic gets past 60 C and the router runs by my estimate 20C above ambient at idle. Removing the laptop battery resolved the issue.
GruensFroeschli last edited by
It might help to enable/disable powerd.
Having a built in UPS is half the advantage of using an old laptop. Seems a shame to have removed it. Was the battery dead? Drawing more current than it should perhaps.
I used to work for a company that made transformers and coils of various types. Occasionally noise was an issue and the solution was almost always to use a polyurethane potting compound. That stuff does not conduct audio frequency vibrations, like almost completely. However it also doesn't conduct heat, like almost completely! ::) You had to take this into account at the design stage, just potting an existing inductor could easily lead to overheating and insulation failure.
The battery is by my guess at least 7 years old. I tested the battery and it was dead, so I pulled it.
I have a large UPS under my desk, so it isn't much of an issue.