Name that Ware, December 2021

The Ware for December 2021 is shown below:

Thanks to Nava Whiteford for once again contributing another interesting and challenging ware.

Happy holidays to everyone, and may your 2022 be an improvement over 2021!

16 Responses to “Name that Ware, December 2021”

  1. J. Peterson says:

    Since nobody else has posted yet, I’ll take a crack at it. Whole slew of analog signals connected via (guessing) isolation transformers to op amps. MCU and USB interface chips. Late 2000’s vintage. The contributor seems to be from a biology/medical background.

    I’m guessing this is the sensor interface board to a medical device with 16 input channels. EEG (brain activity) is the first guess, because it typically uses this number of channels (up to 256).

    • Allen Smith says:

      They look like they are being very careful with that signal from each channel. Then there is that beefy transistor. Could it be a 16 port POTS to IP phone gateway and that beefy transistor is to send ring voltage to old telephones?

  2. archels says:

    Sixteen high voltage output channels, typically these little step-up boards can be found in CCFL backlight supplies, so they could be driving some light show. There are also some experiments in biochemistry (like blotting) that require a HV supply, but afaik not in the kV range (which I gauge the outputs of these boards at).

  3. Ingo says:

    I would guess in the opposite direction: 16 channels of high-voltage output because the diodes+capacitor arrangement in the center looks suspiciously like a voltage doubler.

    Maybe a sequencer for neon lights?

  4. Bruno says:

    Question from an absolute beginner and amateur: Can I learn something from the change in color in the PCB? Does it have a purpose / effect?

    • LW says:

      For the high voltage section, it is missing the (typically green) soldermask. This, along with the slots cut out in the PCB increases the voltage isolation between components and channels, allowing the designer to cramp the high-voltage stuff more densely without risk of flashover. The green soldermask is usually more conductive than the raw PCB material and air, hence it improves isolation without the soldermask.

    • Don Straney says:

      The difference in color for the high-voltage boards is because they don’t have a layer of soldermask on top: essentially dye and epoxy I think, which is what gives PCBs their typical green color. Its whole purpose is to improve soldering process control, by not letting the solder that’s supposed to be going on a joint instead flow away down the trace(s) connected to it. Soldermask also makes it harder for the solder to stick to the bare board in between pads and form unwanted bridges.

      The reason it’s left off of the high-voltage sections is probably about the high-voltage properties along the surface (normally quantified as CTI, https://en.wikipedia.org/wiki/Comparative_Tracking_Index). I’ve used normal PCB substrate and soldermask for pretty high-voltage stuff, but that’s been where there’s room to spread it out and go overkill with the creepage distances (https://pcbdesign.smps.us/creepage.html), and in prototypes that would be used only in a clean lab environment and didn’t need a 10-20 year industrial equipment lifespan. If you’re trying to put high voltages across small distances as in this design, and deal with dust buildup etc. over the instrument’s full lifetime (especially with that fan blowing outside air straight onto it), then you have to be a lot more careful about making sure it’ll be reliable. I’m guessing it’s just easier to find high-CTI PCB material and skip the soldermask (which can’t be trusted as good insulation anyways), than to find both a high-voltage-qualified PCB material and *also* a high-CTI soldermask.

    • Hales says:

      Yes.

      The circuit board itself is a tan colour. This is the colour of the resins and fibreglass that make it it.

      The green colour isn’t actually the circuit board. It’s just a layer of paint on top called “soldermask”. Solder is phobic of soldermask (ie it doesn’t stick), so it can help avoid solder bridges between nearby copper pads. It also insulates copper tracks against accidental contact with other parts, dirt, debris and stray fingers.

      They have avoided putting soldermask on that central area of the image where the high voltage circuitry is. Perhaps their soldermask isn’t rated to work at high voltages?

  5. Quail says:

    With the physical separation gaps it in looks like higher voltage to me, with all the in chips I’d say it is definitely signals that matter ie. data.

  6. FETguy says:

    Looks like a board from a Caliper Life Sciences Labchip electrophoresis system. Transformers and HV circuits look the same as an 8 channel board I see on Ebay.

    • Don Straney says:

      Wow, that is 100% spot on. Nice work.

      I could tell it was a bunch of HV-generator channels (the voltage-multiplier-like circuit layout, separated windings on the transformers, and the extra-long diodes gave that away) on some kind of bio lab equipment, but wasn’t sure where to go from there.

      • FETguy says:

        At first I thought it might be some sort of piezoelectric driver, maybe phased array ultrasound. But that didn’t last long, because I realized that the voltage doublers cannot change polarity, or change output voltage anywhere near fast enough for that. That also lets out various exotic visual displays. The transformers look like the ones used for CFL backlights, but generally those are not rectified and anyway, who needs 16 small programmable channels of that?? Then I thought about electrophoresis, and it was pretty quick after that. Design/build quality matches that of typical scientific instruments. I like the driver circuits, and would not be able to resist tracing out the circuit if I had one around. I think the transistor and 5.1 ohm resistor is a current limiter in case the cell gets shorted. I can’t quite read the number of the 8 pin chip with the Siliconix logo, but I think it is a 2 channel analog switch, so maybe that selects output voltage, or maybe it is just channel control with voltage set by a DAC somewhere.
        I sure enjoy this monthly game! Don, those were some nice boards you contributed earlier this year!

    • archels says:

      Oops, looks like the voltages used in electrophoresis do in fact go all the way up to a few dozen kilovolts! Great fun playing as always, cheers!

  7. LW says:

    Interesting puzzle. I see a 16-channel ADC on the top left along with what seems like an Intel microcontroller. Two PLCCs from Atmel at top center with different SRAMs, apparently the bottom one from Cypress being dual-ported. A Cypress FX2 providing USB connectivity I think, with the FIFO lines probably connected to the dual-ported SRAM for bulk data transfer from the host.

    The 16 HV channels seem to be generating voltage, though I’m not sure to what range and what sort of waveform. We see a 751 used as a regulator (?), with a bank of resistors used as feedback for the LM324A to generate different gains or reference voltages.

    The Fairchild IC is probably used to generate the required waveform, which is then fed to the step-up isolation transformer and a voltage doubler. I’m likely wrong with this though, there should be some sort of feedback from the transformer in these sort of designs, but I can’t seem to find it… maybe I’m wrong with either the purpose of the op-amp or the Fairchild IC.

    Curiously there’s a Channel 17 on the bottom right of the image that is of the same connector the other 16 channels use, but without the HV stuff?

    There’s mention of a DDR with a P38 designation, so it looks like maybe a DIMM slot is somewhere to the right of the image. Though that will be odd as this suggests there’s something with more heavy-duty processing capability onboard other than the microcontrollers shown in the image, but it already seems like the USB connection interfaces with the SRAM and PLCCs.

    Unless the FX2 is only used for programming the PLCCs? Then there’s just the fan and mains input on the right side of the image, which will be in the middle of the entire PCB. Then fan would then just be circulating air within the case and not used as an inlet/exhaust I guess. Wow this is puzzling.

    Bruno asked about the change in colour of the PCB. For the high voltage section, it is missing the (typically green) soldermask. This, along with the slots cut out in the PCB increases the voltage isolation between components and channels, allowing the designer to cramp the high-voltage stuff more densely without risk of flashover. The green soldermask is usually more conductive than the raw PCB material and air, hence it improves isolation without the soldermask.

  8. Ratz says:

    Happy New Year Bunnie and all contributing/lurking geeks.
    My 2p would be on an ECG or EEG machine.

  9. defunct says:

    My guess is an analog telephony line card.

    The ROM operates at 5v and the POTs look like they can be manually switched if needed (to match a customer’s needs?); also, in the lower right-hand corner the board is angled which could mean this daughter board gets slotted into something.

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