Recent Posts

1

Projects, Designs, and Technical Stuff / Re: Transistors - die pictures

« Last post by ricmm on Today at 03:57:32 pm »

Hi, I hope this is the right place to post this.
I've decapped a jfet from an electret microphone from an old Samsung mobile phone. I have no idea about the exact part model, but I think it should be like any other electret mic jfet (2SK596 and alike), so there have to be a diode and resistor between gate and source.
I'm not sure about each structure in the photograps I've done 
Someone could help? Thanks.

Not very good picture of chip marking, sorry:


Die size about 330um x 330um

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Embedded Computing / Re: Graphical Calculators running basic

« Last post by RAPo on Today at 03:56:23 pm »

The HP-prime has TI-basic

https://youtu.be/FJwkoDKlh8Q

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Projects, Designs, and Technical Stuff / Re: MCU recommendations- looking for low pin count with more memory than ATtiny

« Last post by hsetlik on Today at 03:55:35 pm »

SO-8 packages tend to be somewhat trailing edge.
If you are ok with SO16N, QFN20, or TSSOP20 there a (lot) more choices.

Yeah was just realizing this- I did a rough PCB layout of the controls and analog section and there's definitely room for a TSSOP20 package, I was leaning towards the STM32G030F6 because it can run off an external crystal rather than relying on the internal RC oscillator like you mentioned.

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Buy/Sell/Wanted / Re: Philips (Photonis) XX1080 50mm Image Intensifier with PSU

« Last post by TimFox on Today at 03:54:12 pm »

These are vacuum tubes, with an interesting combination of photocathode, accelerating electrodes, and phosphor (electron-excited light emission) construction to give more light out than input, preserving the geometry of the light pattern hitting the photocathode.
There are different construction methods, including microchannel plates, that are used for this purpose that require reasonably high voltage to accelerate the electrons.

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FPGA / Re: Help on translate schematics to Verilog.

« Last post by caius on Today at 03:50:27 pm »

Though sluggish, it looks ok.

You do realize that going through a logic gate delays your clock, right?

Yes, I do.

You also know that the max10, even the slowest one, runs it's logic something like 10x faster than the old 74LSxx ttl logic you are trying to replicate, right?
Did you know that on the max10, you can set IO slew rates and output drive currents for the IOs?

Yes, I know.I made man other designs (mainly with MAX7000S CPLDs) and sometimes I fixed them by enabling the SLOW SLEW RATE option.But in this case I did not the trick.

What does your logic look like?  Maybe it is not clock noise, but a logic delay which you require.  There are means of doing this inside the max10.

I made the hardware part of this custom IC replacement, it runs Verilog code from someone else who decapped and tracesd the original custom IC.Perhaps I do need a logic delay.I tried other TTL (like inverters) but I  totall fixed the issue using a 74LS367 in the above configuration.How can I add logic delay inside the MAX10?As said, plaing with slew rate did not change anthing.Thanks.

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Thermal Imaging / Re: Fraser now has Linear Flash PCMCIA card read/write capability if needed

« Last post by Leolo on Today at 03:50:05 pm »

Has anyone been able to write old "series 2" linear flash cards using a PCI to PCMCIA adapter in a desktop computer??

Those old flash cards need 12v to write, and it seems that not all adapters are capable of supporting that voltage.

I'm thinking of getting a BUFFALO WLI-PCI-CA adapter, which is relatively inexpensive. I believe this adapter was initially sold with a wireless PCMCIA card inserted from factory, but some stores sell the adapter "empty" without any PCMCIA card inside.

This Buffalo adapter has a RICOH R5C475II controller, it also has a Texas Instruments TPS2206 power-interface switch, and nearby there's also a Linear Technology LT1086 adjustable regulator. Both the TPS2206 and the LT1086 chips support 12 volts, so I'm inclined to believe that there's hope that this adapter could write those older Linear Flash "series 2" cards using 12 volt

What do you guys think? Is there any hope using these PCI to PCMCIA adapters? Are there other adapters that you've verified to work with Linear flash "series 2" 12v cards??

I have many old computers with available PCI slots, but unfortunately I don't have any laptop with PCMCIA slots

Kind regards.

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Metrology / Re: Help to identify the triax connector on an ADCMT 5450 electrometer.

« Last post by aronake on Today at 03:49:18 pm »

After some experimentation I figured out what was wrong with the cables I made. On the triax cable I have the innermost conductor have two layers of insulation to the guard. The inner one is the PTFE (white/transparent typical PTFE colour), the outer one  is quite conductive (black). I thought there was only one (the black) and tough that it was black PTFE. Not removing that made terrible amount of leakage.

Once i got the black insulation removed and only the white PTFE left, it was easy to make cables that max out the meter. Even at 1000V the leakage current is below measurable threshold and hidden in noise. The meter jumps around between around -10 to +10 fA.

Probably many people here knew already about this double insulation, or it may be from triax cable to triax cable, but this may be useful information for someone.

And thanks to all here on input on how to find (or make) the correct triax connector and on leakage currents.

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Test Equipment / Re: SDS800X HD Actual Use Cases

« Last post by mawyatt on Today at 03:47:36 pm »

Would expect so, as it's already been shown how to make Impedance and Admittance measurements utilizing the Bode Function.

One could use a current probe for the current measurement for V/I or I/V plots, but also a simple small sense resistor works. The 12 bit resolution, low noise, and large dynamic range (range scaling) come into play here.

If Siglent makes a firmware update that allows the math channels to be part of the Bode Function, then this opens up a lot for direct use cases without need for additional support probes/components/equipment.

As we noted on numerous occasions, contrary to some naysayers, this Bode Function is extremely useful in the hands of knowledgable users

Best,

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Projects, Designs, and Technical Stuff / Re: MCU recommendations- looking for low pin count with more memory than ATtiny

« Last post by hsetlik on Today at 03:46:48 pm »

The CH32V003J4M6 is a RISC-V MCU made by WCH that costs below 20 cents, but you need to purchase a cheap dedicated debug probe (around 4€). There are tons of code examples and many people supporting these chips.

Yeah the CH32V003J4M6 looks promising, nice that it's compact and low cost but I did a rough layout of the PCB analog section and realized I can comfortably fit a TSSOP-20 package, so I'm leaning towards the STM32G030F6 now. The ST is more expensive but the CH32V003 isn't available from Mouser or DigiKey and I'll only be making a handful. For the price I probably will order a CH32V003 probe just to experiment.

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General Technical Chat / Re: Powering an LED from international line voltage

« Last post by xvr on Today at 03:42:43 pm »

I'd peek some circuit from one of PE article. It can solve here.