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1
Microcontrollers & FPGAs / Re: Learning FPGAs: wrong approach?
« Last post by BrianHG on Today at 11:48:22 AM »
Now i feel like everything i've learned about HDL is wrong.
I use Verilog to make my life soooo much easier.  Especially if you use a simple single synchronous clock for everything, nothing asynchronous.  Coding this way make very portable designs across all FPGAs and PLDs.  As for the above VHDL example, it twists my head and I avoid it at all cost and wont ever use it.
2
Test Equipment / Re: $7 DT9205A?
« Last post by kalel on Today at 11:48:06 AM »
Quote from: JLNY
Instead of using hot glue, one might also use a couple layers of adhesive-lined heatshrink tubing instead. Done correctly, it can make for an excellent strain relief, and I know it is often used in industry to ruggedize things like higher-end and phase-stable RF coax assemblies.

The idea is to have multiple layers in such a way that the strain relief still flexes along its length, thereby actually increasing the bend radius rather than just shifting the strain point farther back like most rigid strain reliefs.

Edit: Added image. not the highest resolution, but you get the idea.

Yes, that sounds best as long as you can get the heatshrink over the probe (that is, if the size that goes over the probe is small enough so that it can shrink down nicely). Otherwise some soldering and hacking would be necessary. Glue gun is definitely not as good as that, but it's also not rigid, so it can somewhat do the same task up to a point.
3
From the article it looks as if it's only a US problem, the rest of the world gets proper Pyrex Borosilicate glass. Worth keeping an eye on the PYREX vs pyrex trademark though.

I put that down to the 'Wiki fuzz' effect. In Australia glassware marketed as 'pyrex' seems to be universally NOT borosilicate. And the company in question presumably calls themselves 'World kitchen' for a reason.

You can get both 'forumlations' of Pyrex kitchenware in Australia; Soda-lime glass and borosilicate, the latter being low expansion and more resistant to breakage during extreme temperature changes. You just have to read carefully on what is on the box. You'll find a lot of those discount shops just sell the soda-lime stuff (although still technically genuine "Pyrex"), thankfully most of the big supermarkets here sell the proper borosilicate Pyrex and it's not really that much more expensive.

For my everyday cooking (measuring liquids or preparing stocks using boiling water) I just use laboratory beakers made from borosilicate. They also look nifty.
4
Buy/Sell/Wanted / Re: FS: Used Tektronix TAS-455 - AU
« Last post by wasyoungonce on Today at 11:43:42 AM »
A big attaboy thanks from me to John!  Scope works a treat and one day I'll be passing this on free (pay it fwd) to another member. :-+ :-+ :-+
5
This is why UK plugs have shutters on the live and neutral which are opened by putting a pin in the earth socket.

You can still defeat that. Nothing is idiot proof, although I did come up with a concept for a truly idiot proof plug design.

To be fair you can do the same thing to Shucko outlets if you have something like a 3.5mm headphone connector, or another round plug. The same thing can also be done to Australian plugs. If one is stupid enough anything is possible.

The blades on an Australian outlet are very similar in size to US outlets, I think this could work as well.

Pretty much every country has a standard for shuttered outlets that people are supposed to put into new installations, but a lot of the time due not do, purely for cost reasons. NEMA has it, Shucko has it.





The Australian outlet is actually very well designed and among the safest in the world. Even without mechanical shutters, the holes are too narrow to fit most everyday objects into (including 3.5mm audio connectors, butter knifes etc...). I'm sure I could find something in my house to fit into the holes that shouldn't be there, but I'd really have to be determined.


6
If power supply current is not a factor, and you want an excellent digital volume, class A headphone amp with a bit of kick, I would use the MUSES, powered at full 30v (+/-15v), have the output drive 2 x 30v ultra logic level (1.2-1.8v) mosfet gate directly operating in voltage follower mode

All that engineering spend on linearity, thrown away. Not that it matters.
Linearity with Darlington BJTs wouldn't be too terrible, but, I like high current drives without feedback when driving cable and low power dynamic loads like headphones.  But, that's just my ears...
7
Beginners / Re: Question on resistor label.
« Last post by MK14 on Today at 11:41:09 AM »
As already stated, a single 2N3055, would probably overheat (the Safe Operating Area of the 2N3055 is probably violated as well!).

Which is why they usually have a number of 2N3055's in them.



http://www.rason.org/Projects/powsupply/powsupply.htm
8
Projects, Designs, and Technical Stuff / Re: The uBeam FAQ
« Last post by BrianHG on Today at 11:39:51 AM »
A few years ago, someone had come up with a "crowd control beam" that caused anyone to be hit with it to instantly loose control of their bowels. I don't know what became of it, but talk about the most effective crowd control method ever!

"When you're looting that TV and you feel a little beam: Diarrhea, diarrhea. When you're marching for a cause and the cops want you to pause: Diarrhea, diarrhea." (To the tune of "Sliding into Home")

It was a VLF inaudible frequency which vibrated tuned to the average dimensions of your gut with embedded almost audible thumps as well.  If I remember correctly, saw it in a documentary quite some time ago.
9
well yeah, how many laptops, PCs and servers would they sell if they were re-named Agilent and Keysight,

while Dell, Acer and the others kept their names, and flogged more gear due to customer brand familiarity and confidence



"oooh lookie at my new Agilent laptop.." 

:wtf:  is an 'Agilent'? who makes it? another new player? stick to the real deal and buy a pro HP or Dell next time..
Can you take it back for a refund, seriously Doris, that orange laptop looks weird "


 :-[



   
10
Test Equipment / Re: $7 DT9205A?
« Last post by JLNY on Today at 11:35:42 AM »
As for the probes, just adding some hot glue can really help make them last longer (as they don't have proper support). It's a cheap solution that really helps. It won't do much about the resistance, however, it's difficult to expect some high end leads and those should last with the glue gun method (hopefully).
Instead of using hot glue, one might also use a couple layers of adhesive-lined heatshrink tubing instead. Done correctly, it can make for an excellent strain relief, and I know it is often used in industry to ruggedize things like higher-end and phase-stable RF coax assemblies.

The idea is to have multiple layers in such a way that the strain relief still flexes along its length, thereby actually increasing the bend radius rather than just shifting the strain point farther back like most rigid strain reliefs.

Edit: Added image. not the highest resolution, but you get the idea.
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