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Is a Wooden Enclosure for Electronics a Good Idea? Answered

I am in the process of converting my ATX power supply into a bench power supply. My PSU's standard case is made from 1mm steel with various ventilation holes, there is also a 120*120mm fan. 
However, the circuit board is strangely positioned within the case and there isn't enough space for what I want to add.  
I would like to take all of the electronics and rehouse them in a home-made wooden case. My question is; Is this a sensible thing to do?
I plan to use 5mm pine stripwood to remake the box, but slightly bigger and better arranged. I would still fit the fan and drill plenty of ventilation holes. 
Do I need to take any extra precautions if using wood, or is it just a really bad idea.

Thanks in advance. 

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Re-design
Re-design

Best Answer 11 years ago

It is  fine to do that.  Keep all of the mains power away from the wood.  It is best if you can keep all of the power lugs insulated from the wood.  Wood is a good insulator but is not perfect.  It absorbs moisture from the air and at times may present a high resistance short.  It should not be a problem

A note:  Most of the original radios were built using wood for a chassis.

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steveastrouk
steveastrouk

Answer 11 years ago

....and TVs and recordplayers, and all manner of scientific instruments.

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ccollins1970
ccollins1970

1 year ago

Just to add a tad more specific detail to what has already been shared. IRON and STEEL are truly unique electromagnetic shielding materials. Today's electronic devices often have busses that are 64-bit wide and many times, several busses that are 64-bit wide. It is not uncommon for these busses to be clocked at 4-GHz. Since Claude Shannon's information theory tells us that more information is provided with greater entropy, this means that most machines doing much of anything "fancy" will have spectral content nearly uniformally distributed below 4-GHz. While the average total power content is within the power capacity of your power supply, peak power at certain frequencies can be high and is often random.

If building a case of wood (I think it can look nice and certainly unique), you will certainly want to line the wood with metal tape. I recommend Copper tape. Since spectral content will extend even to mains frequency and to AM and FM radio frequencies, I recommend THICK copper. You could mount the wood chassis inside of a more universal one-size-fits-all Faraday cage if desired, but this would take considerable space and certainly wouldn't save money unless you happen to have some chicken wire lyin around or an unused Faraday cage.

As others have stated, wood is not at all a good thermal conductor and is notorious for its moisture absorption that makes it swell ands makes it a tad bit electrical conductive, and if your enclosure were a house, the building inspector would require gypsum board for flame retardency since would makes nice camp fires and sadly nice house fires. I don't know that you'd want to sheet rock your enclosure though. That'd make the whole effort not worth while.

ONE REASON NOT YET MENTIONED.

Wood is considered tribogenerative. While not as bad as wool, static electric can develop when materials rub against wood. One advantage wood has in this respect is that it doesn't have extremely high ressitance like Teflon so it will dissipate the charge slowly, but if too much rubbing occurs, high electric potentials could develop and could arc to the enclosed electronics. This is a low risk, but it is a risk that the uber sensitive electronic labs have to consider and even adhere to avoding wood in their labs to be certified.

On a random note: Wood is fairly electromagnetically transparent so it can make pretty respectable antenna radomes and masts, but this also stands to an example why they make poor enclosures.

Another small detail: Pressure treated wood is commonly treated with copper, but trivial amounts, and hardwoods are rarely, if ever, pressure treated, and hard woods look nicer for enclosures and are sturdier with smaller boards and absorb less water. Purple heart has the lowest moisture absorbtion but is rather costly. Oak is more practical.

All of this being sad, we can see why so few electronic enclosures, if any, today are wooden. I miss the look of old radios and old scientific instruments, but conducted and radiated emission spectrums got broader band, and we got wiser as a society (to some extent, and this is one).

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seandogue
seandogue

11 years ago

Based on your background information for the question and the question itself....

For modern, high-power, EM radiative equipment? In my opinion, it's not a "good" idea even if you can get away with it. Steel has a nice thermal conductivity, wood does not. Steel provides a loverly magnetic shield (basically an extension of the faraday shield, although not perfect), wood does not. Steel will burn, but not at the moderately low temperatures available from a failed homebrew circuit board or accidental short circuit. The same cannot be said with any credulity regarding wood.

BTW, a 1930s radio operating at several hundred kilohertz doesn't even come close to comparing with a modern computer or its switching power supply in power, in spectral content, or in transmissive properties.

There's a reason beyond mfging that steel cases are the norm for desktops, and that relatively low power, mobile-based, battery operated laptops are well shielded.

Bottom line is, as cool as modern electronics are, they are the E-M equivalent of connecting everyone's raw sewage pipes directly into streams and rivers.

I would advise you to reconfigure your wood case to house the power supply as it stands, then apply the additional circuit board outside the PSU, but within your wood case to reduce the "system's" transmission of radio noise retaining the ventilation holes you indicated.

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Burf
Burf

11 years ago

Wood can made into an excellent PC case. I have seen some custom wooden cases that were furniture quality pieces.  The only suggestion I have is to allow plenty of room inside the case for air circulation. The wood acts as a thermal insulator and you'll will need plenty of air volume to keep things inside cool.

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NachoMahma
NachoMahma

11 years ago

.  If you get RF interference from the unit (very possible with a switching power supply), shielding the inside of the box with metal (Aluminum foil, sheet metal, &c) and grounding the shielding will help.