I remember that advice from building computers - use a very thin evenly applied layer. However, in my case, I apparently used too thin a layer as it didn't fill in all areas and left some air pockets. So a little squeeze out is better than not enough 🙂
I think you mean lock washers. I haven't used them. I use fender washers, I find, at least with sil-pads, they distribute the torque much more evenly than without.
I have noticed they never need to be retorqued but IMO it's just good practice to check.
you MUST use fender washer , but - beside fender washer - I'm using lock washer to ensure constant pressure - even if I'm mostly using mica & goo
funny - I found that old ( non valid , but also even valid
) coins are best for purpose .... almost as they are last pieces from personal stash of Baron Krupp ...... 
funny - I found that old ( non valid , but also even valid
) coins are best for purpose .... almost as they are last pieces from personal stash of Baron Krupp ...... Attachments
you MUST use fender washer , but - beside fender washer - I'm using lock washer to ensure constant pressure - even if I'm mostly using mica & goo
funny - I found that old ( non valid , but also even valid
Way to throw money at the problem!😉
you MUST use fender washer , but - beside fender washer - I'm using lock washer to ensure constant pressure - even if I'm mostly using mica & goo
funny - I found that old ( non valid , but also even valid
What are those white insulators on the joints to the mosfet?
Jim
I believe I said Papa also uses...
I beleive the term is Socket Head Cap Screw. The ones pictured look Stainless or plated. "aircraft nuts" is not even found in Wikipedia??? The English term would ussually be screw or possibly bolt. I did not see any nuts of interest? Aicraft or otherwise. Ummm, were you thinking of balls to the wall 😀
That looks like a spilt lock washer ZM. There are other wavy looking " springy" washer devices that can work well but, you need to keep equal pressure all around and if not sized properly they won't be.
I guess the real reason for this post, other than feeling piled on when only trying to help, can be found in the Zen Version 8 article, by The One an Only himself: "Q2 is mounted on a heat sink like any other power device, but we pay special attention to the mounting of Q1. I mounted mine directly on an anodized sink, using thermal grease and about a pound of pressure from a clip."
AaHmmm
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I think "Aircraft-Grade" as is "Surgical Grade Stainless" and "Used by NASA" are terms used to sell everything from Tempur-pedic mattresses to Ginsu knives.
And, traditionally Socket Head Cap Screws were easily available in SAE (Probably only a North American standard) grade 5 stainless or grade 8 carbon black. Very good quality stuff. Today however you can get cheap copies and plated decorative ones of all types.
When I experimented with the LU1014D I used a clamp, with a screw, as in the profile view below. The JFET has no mounting hole,
When I experimented with the LU1014D I used a clamp, with a screw, as in the profile view below. The JFET has no mounting hole,
Attachments
It is. It did have problems with the original CPU dies which had components on the top (the so-called 'naked' dies). All modern CPUs have heatspreaders - this is less of a problem now. Still, you never know.
From the horse's mouth:
Arctic Silver Incorporated - Arctic Silver 5
I use 100 to scuff up the surface and then lap it finer. The lapping to very fine is probably not necessary - I really would not go above 800 for a 30 watt device the size of a TO3-P. The difference will be insignificant. Mirror finish emerged at a time when CPUs were pushing out around 60 watts out of a surface the size of a TO-220 contact tab, or even smaller. There even the slightest differences could be measured and seen - through a fried CPU, mostly.
It is surely possible to do it, but I'm not sure it provides any additional benefit in terms of device temperature. It should look nicer, though 🙂
I ran up a quick sim on LTspice, with the load changing from 1.3A (the quiescent drain with no output) to 6.3A (add 5 amps load). Didn't see any signs of ringing or other nasties, just the output voltage drooping by a fraction of a volt or so. Going to try and do some screen captures and put them up here.
grade 8.8 are the lowest quality high tensile bolt material.
Mild steel is about grade 4.6
Socket head cap screws and aircraft spec bolts are usually grade 12.9 or 14.9
14.9 is roughly 96% stronger than 8.8
and
8.8 is roughly 160% stronger than mild steel.
Mild steel is about grade 4.6
Socket head cap screws and aircraft spec bolts are usually grade 12.9 or 14.9
14.9 is roughly 96% stronger than 8.8
and
8.8 is roughly 160% stronger than mild steel.
Are we torquing truck tires or military aircraft egress/environmental equipment down or simply snugging up a plastic wafer?
Ok, you could probably achieve that specification with nylon fasteners.
I'm guessing that aircraft grade fasteners are not required. 🙄
Is this a good option ?
An externally hosted image should be here but it was not working when we last tested it.
no.
That and all the other ideas are "shake proof" to prevent vibration loosening the screwed fastening.
Belleville washers are designed and sold for this force regulating job.
That and all the other ideas are "shake proof" to prevent vibration loosening the screwed fastening.
Belleville washers are designed and sold for this force regulating job.