Low Cost PCB's Low Cost Components

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Cheap being a relative term ... Paid ~ 300 EUR for all the copper tape, but commercial units with lower resolution cost thousands.
Generally an interesting project, that I though was worth a video :)
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General Chat / Carbon M1 3D Printer
« Last post by Homer J Simpson on Today at 12:56:48 AM »


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General Chat / 9V Lithium rechargeable batteries
« Last post by BradC on Today at 12:55:46 AM »
G'day all,

I chew through 9V batteries. Back in 2011 I bought 8 Powerex Imedion 9.6v 230mAh batteries and a charger and they have been good, but very variable. Some of them have averaged 80-100 hard cycles each in objectionable thermal conditions and have paid for themselves many times over while others might have done 10 cycles and are completely dead. Now I'm down to 3 working batteries which are averaging about 130mAh. Still barely passable for short term use, but pretty duff overall. I was looking to replace them, but the lightly used ones just haven't lasted like I might have hoped.

I've been looking for a long time at the new Lithium Ion 9V batteries, but all I could find were E-bay specials which looked over-hyped and liable to die quickly.

My devices all go into low-battery at about 7V and so I was also worried about the 7.4V nominal battery voltage. 8.4V NiMh were almost useless in these devices. I was poking around looking for something else and discovered these : https://www.master-instruments.com.au/products/63235/LP702235-BP1.html

Rated at 500mAh, supplied by a reputable supplier in Australia and actually have a real data sheet (which initial measurements indicates might be accurate). I bought 2 and a charger from a store on E-bay as a test.
A couple of cycles with a 100mA discharge load sees them running out to about 550mAh with 500 of that above 7V. Devices are happy.

Time will tell how many cycles I get out of them but at the outset I'm already fairly impressed.
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Repair / Re: Help identify Fairchild mosfet
« Last post by texaspyro on Today at 12:55:33 AM »
Hint: it can't be made in 1953, and there's no 53rd week of any year.

Wanna bet?   365 days / year divided by 7 days per week -> 52.14 weeks per year (52.28 for leap years).   That .14 is week 53.

I had some Sylvania LED light bulbs that were recalled.  The CPSC recall bulletin listed affected date codes.  I had some bulbs with a 53xx date code and were not listed in the CPSC recall bulletin.  I sent them an email and within two days they updated it to include the week 53 bulbs.   Amazing response time from a government agency.
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General Chat / Re: New (and better) GPS half the price of a new map!
« Last post by JPortici on Today at 12:52:52 AM »
...more to the point... do people still use dedicated GPS units for vehicle navigation?  :-DD

i really wish they all used google maps + autovelox addon.
Instead, they all seem to rely either on tomtom, which always suggests retarded routes and NEVER updates it if you decide to go against it or you make a wrong turn, or on garmin which has inaccurate maps.
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It would be great if people from here tried reaching out, especially those that run a more corporate setup. I'm sure Mikrosens would be interesting in dealing with a business a lot more than a bunch of nerds.
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Test Equipment / Re: Advantest R3131A Spectrum Analyzer 9KHz-3GHz
« Last post by IRB on Today at 12:49:55 AM »
I have an R3131A with TG, after about 10 minutes the TG signal drops out.
I have pulled all the cards out of the chassis, and the power supply.
 Nothing appears burnt.
 Nothing smells burnt.
 Pass power up self tests.
 Passed self Calibration.
 
I put the power supply back in. I noticed voltages silk screened on the Buss PCB, on the side where the display was connected, behind the display.

                 J10   +5.2V   +12.6V    and    J9  -12.6V    +24V

I measure           +5.24V  +7.41                   -12.66V  +24.27

There is an unmarked pin on J9 that is 2.29V


The supply is marked AT120-5224/M NEMIC-LAMBDA
The supply looks like several switcher supplies in one.
I'm thinking it's a bad regulator.

I like to know if anyone has and can share a schematic for the power supply?
If anyone has a fixed a similar issue, and has advice?
 
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Spirit532,

Agreed.

The availability of easily purchased and low cost thermal imaging sensors and/or cores would be excellent. There are many applications that do not require super low NETD figures.

If thermal sensors could be fabricated anywhere near as cheaply as conventional CMOS visible light sensor arrays it would be a major step forward as the technology would find its way into all manner of products. You could have 'smart' intruder detection sensors rather than simple PIR's. Cars could have thermal vision driver assist and the science community could make all manner of interesting 'detector' assemblies. Such a sensor might also force a lowering of prices in the microbolometer marketplace.

As with all new technologies, there will be a period of development followed by fine tuning and enhancement. This is no different to the early days of BST and microbolometer based sensor technologies.

An interesting development. Thanks to the OP for highlighting it. Mikrosens also have patents for diode junction based thermal sensor arrays.

Fraser
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I read the paper, two guys in the US and Japan did similar work in 1999...

Steve
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General Chat / Re: This was not what I expected
« Last post by dmills on Today at 12:44:24 AM »
Sometimes, the really "gold" & shiny ones are fake ones because they want it to stand out over the real ones which normally have some minor scratches on the surface.
Yep, bright, shiny, and very slightly the wrong thread pitch or pin diameter, been there, done that.

Connectors are enough of a minefield these days that just buying from Rosenburger/Huber & Schurner/MA-COM becomes increasingly attractive.

Regards, Dan.
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