Engineer creates first custom motherboard for 1990s PlayStation console https://arstechni.ca/NBSz #electronicsengineering #hardwarepreservation #Reverse-engineering #Vintagecomputing #hardwarehacking #retrocomputing #classicgaming #GamingHistory #crowdfunding #Gameconsoles #PlayStation #retrogaming #opensource #PCBdesign #retrotech #Gaming #gaming #Sony

I needed a bit of distraction, so why not go ahead with the bi-yearly gear power-up

So today is the day where you power up your precious instruments you don’t use too often, thereby preserving the capacitors in power supplies, analogue circuitry, etc.

It doesn’t take long, an hour will do it

Yesterday was #worldmetrologyday and thus, a perfect occasion to do the monthly statistical readout of my four 10V references, based on the popular LM399.

Two of them arrived January 15 and has been powered since. A couple of months later, March 22, I added two more. The idea is, that the standard deviation (noise) of the 10V output should improve with time, lots of time

Well, that is in fact what I see. Three of them are now at 1.15uV, 1.17uV and 1.45uV.
The fourth however, started out really high, 81uV , but has since improved to 29uV in just two months.

I plan to keep doing this, - Let’s see what the rest of the year brings

Long term plan: a 10V calibration transfer

Powering up a blue laser diode to 500mW
Note how it acts like a poor LED until 150mA, at which point the laser process fires

The 505B is an accurate, adjustable current source which allows for external modulation input.

It’s designed for low-noise (<1.5uA RMS) and it has a photo diode input, so with a calibrated light sensor, you can achieve constant power regulation.

Last but not least: it’s designed for maximum safety with two interlock circuits, one with a physical key.
Its internal design has a complex redundant output circuit, which ensures that the laser will NEVER illuminate unintended and it will NEVER exceed the chosen power setting.

A fancy current source indeed, a laboratory grade instrument

This video was shot wearing the appropriate safety glasses, be VERY CAREFUL when experimenting with lasers. Even a short duration reflection at this power level WILL damage your vision

Got my hands on this little gem recently, they’re hard to find in a decent state at a decent price tag. Got lucky though so now I have a dedicated laser diode driver in my lab
Not super high power, it maxes out at 500mA, but it’s enough for a whole range of experiments and it has a lot of nice safety and control features
It’s surprisingly complex inside, but nicely built and very clean. Doubt it’s seen many hours usage, the fan is just fine
#electronicsengineering #laser #testandmeasurement

Adding parallel circuit allows for the Lambda Diode to oscillate at a frequency determined by the LC resonance frequency. The result is an absolutely beautiful sine wave

Note how the oscillation starts, once the supply voltage crosses where the current starts to decrease, ending up at the ‘negative resistance’ portion of its characteristic.

This is likely the easiest and most clean oscillator I ever built I wonder if you can use a crystal or crystal f it would get damaged from the drive level
Maybe one of those vintage ones..

@va3db

Stumbled across an article describing the ‘ADALINE’ #perceptron emulator, an analogue circuit, made entirely by a resistor and potentiometer network.

Being from the early 60’s, there’s not much information to be found these days on the device, but I managed to build it pretty much the way it was - at least I think so

It’s quite fun to train and test with different patterns - units like these are the vintage foundation of modern neural networks, AI and language models.

Baby steps in getting my Apple I reproduction PCB up and running. 6502 CPU booting with just RAM and ROM attached. It grabs the reset address from ROM and starts executing code...until it tries to do something with IO, which is not attached yet...

I'm monitoring the bus with an Arduino MEGA attached to my MacBook Pro.

So when you have a bunch of jellybean JFETs (2N5457), time to burn, and a handful of 1uF bipolar capacitors…
What to do..

I decided to build a simple amplifier Although many find JFETs aren’t quite as intuitive as a regular BJTs, they’re not THAT scary and they’re easily biased, using a megaohm sized resistor from the gate to ground.

To be able to do some more accurate calculations, I decided to measure the maximum drain current, IDSS, and the negative Gate-Source cut-off (pinch off) voltage, as they can vary significantly even between devices even from the same batch.

A fun evening in the lab

As somebody who suffered the torture of the maths part of an Electronics Engineering degree, I can honestly say this is the only time a Laplace Transform has made me smile.

This weekend was special: yesterday the baltic countries: Estonia, Lithuania and Latvia, disconnected from the Russian/Belarus 50Hz power grid, going ‘island mode’, controlling the 50Hz grid frequency themselves.

After more than a day of different stability tests, this afternoon, just before 13:00 CET, a connection to the European grid was established via Poland, so now the the three countries are in 50Hz sync with Europe.

I observed a small, undramatic, ‘burp’ in the frequency at the time of the event, and my wall socket is now in full sync with the measurement in Estonia, provided by #sympower️

I need a reasonably clean 4MHz oscillator for a #hamradio #foxhunt offset attenuator and decided to build one based on a J310 J-FET transistor.

The output on the Drain is quite clean, but can’t be loaded much, so a I added a simple buffer based on BC547B

It’s all pretty standard circuitry, and you can find all kinds of variants out there, but it’s still fun to see it spring to life

Back to work on project Chowndolo! Improving the PCB design and making refinements using KiCad. Excited to take this to the next level...
#PCBDesign #KiCad #OpenSourceHardware #Electronics #Engineering #HardwareDesign #Maker #DIYTech #EmbeddedSystems #CircuitDesign #TechInnovation #ProductDevelopment #EDA #SchematicDesign #Prototype #IoT #DIYEngineering #ElectronicsEngineering #SoundArt #DigitalLutherie #MusicTech #ExperimentalSound #DIYInstruments #ElectronicMusic #InteractiveSound

My first #HB9CV #antenna, believe it or not, made from 5mm brake lines and a foot of 15mm copper pipe

I need it for a 70cm radio #foxhunt event in a couple days - looked different places for design guidelines, some of them came up with quite different results

Decided to just have go at it, based on a combination of what I could find in the legendary #Rothammel antenna book and some online sources and it turned out quite well

Resonance is a bit low, 431MHz, but it’ll do fine as a direction finding device: what I really want is the characteristic kidney shaped radiation pattern, allowing me to turn the antenna backwards, looking for a minimum in the received signal.

Funny to see how the #smithchart impedance plot has a distinct turn at the resonance frequency

Been debating a loooong time whether to get the SV4401A 4.4GHz VNA.. I already have a 4GHz NanoVNA, but the display size, ruggedness and N-connectors on the 4401 is a major upgrade..

Well, I took the leap!

And why not make the first-light ‘Hello, World’ test a fun one I came across an AT-741 aircraft IFF transponder antenna and it seems like it still works

Still in production by several vendors (fx Harris), the unit I have is old, dated 08/1979. So much more fun to have it sense a bit of RF so many years down the road

Yay! The 432A power meter works just fine and I managed to scavenge some probes and the needed connection cable - my first calibrated power meter ever

What a beautiful addition to my little lab

I have more probes and together they cover all the way to 18GHz

Occasionally you come across a rescue scenario: it was literally me or the dumpster… So I adopted it, I now have a 20GHz frequency counter…

The 5361B was never made for normal RF use, its primary application is analysis of pulsed radars. It does, however, fully support CW measurements, so although somewhat bulky, it’s a nice instrument to have around in the lab

#Metrology friends, any good suggestions for a gold plated banana jack? I found these from QED, they look promising #electronics #electronicsengineering