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Need the connector series that connects into whatever connector is pinched between your fore and middle finger in that pic you posted earlier. That is the connector we would want to plug into this adapter PCB.
In EasyEDA look up these supplier part numbers in the library

Why wouldn't we just plug the JVS/JST VL end of that cable into this voltmeter PCB?

The PCB is already designed that way. JST VL input connectors on the back along with the ATX connector heading. JST VL output connectors in the front.
  1. If you are using an ATX PSU to power a Naomi, you don't need to solder in the JVS power input connector in the back of this PCB
    • You only need to solder in the power output connectors and the ATX power header
    • The voltmeter can be installed, but largely for cosmetic value as you cannot adjust ATX power
  2. If you are using this to meter your Sun PSU or whatever PSU,
    • Then you'll want to solder in the JVS power input connectors
    • Not solder in the ATX power header
    • You'll then want to solder in the voltmeter and the 3P3T switch so you can meter +3vdc, +5vdc, +12vdc
  3. Or you can just solder in all components to use it flexibly as you see fit
In all the scenarios above, you'll need to crimp JVS power cables that will connect from this PCB to your Naomi.




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In all the scenarios above, you'll need to crimp JVS power cables that will connect from this PCB to your Naomi.
Yea, I don't think you can get the correct gender in solder pin (only crimp) for a direct connection anyway.

It would be pretty cool if the PCB COULD plug directly into the Naomi tho...
Effectively changing this HARDer to source connector with something else/more common.
Be it ATX PSU connector, OR (wishful thinking on my part) a Molex Mini-Fit Jr header(s) with VLX-AWSD pinout for a direct Molex harness. :D

In addition to the other features added, I can't help but think the "ultimate" version would somehow include this (direct connection).
Personally I HATE crimping shit, I'm a solder kinda guy...
I believe by using existing power connectors (like for example what's used in fully modular PC PSUs for GPUs) crimping could be avoided completely.
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Yeah, unfortunately, JST doesn't make board mount plugs for the VL series. There are only board mount receptacles for the VL series. Otherwise, heck yeah I would make it so it just plugs into the NAOMI. I suppose there can be some experiementation done with just the plugs and pins. But the hard part is the tolerances needed to get the PCB to fit the connections exactly. That is no easy feat.
But do all three JVS voltages come off the modular power connector?
Well you would set your own pinout/spec, assuming you did workout directly connecting the PCB to the Naomi.
Lets say you used a PCI-E/GPU 8-pin cable (PC market pre-made/to avoid crimping anything), you could lay it out something like this...

3.3vDC Ground
DC Ground12v
5vDC Ground
5vDC Ground

This keeps the power lines separated by grounds, providing one 3.3v line, one 12v line, two 5v lines and 4 DC ground lines.
That combo (1,1,2,4) is how Taito dose it on the official JVS harness.
I'm thinking because Naomi sucks more 5v than anything else.
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Let's do that instead then. The right angle 24 position ATX connector is a whopping $11-15 USD!!! So there is some serious cost savings. However, that does preclude that folks will have to use a more expensive PSU and will have to meter out their connectors to ensure they have the right power. And and and and folks have to know to ground pin 14 of the mainboard connector so that power on state is achieved with the switch.

But this way, the connector is a whole let less bulkier and you can find a used modular PSU for next to nothing.
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Or crimp your own for pennies. But you know, crimpin' ain't easy.
I found a PCI-E cable from one of my modular ATX PSU's laying around and plugged it into the power connector for a MiniGun. That's the connector from Frank_fjs's MiniGun and is what I am using for this PCB. It's a perfect fit, latch clasping and all.


Furthermore, I metered out the PCI-E cable to ensure that it uses pass thru wiring. It does. That means the wire on either end of the connector, the same wire goes into its mirrored position number: So on one row, position 1-2-3, the wire from position 1 goes into position 3 on the other connector. Wire from position 2 goes into position 2 on the other connector. Wire from position 3 goes into position 1 on the other end. So I made sure to adjust the nets on the Mini-Fir Jr connector and followed this pinout for an Corsair ATX PSU (Peripheral & SATA):


This PCB has:
  • Copper pours for the GND plane and the +5vdc plane
  • Multi-layer solder pads for the voltmeter connector wire
    • Allowing you to install the meter on either side of the PCB to suit your needs/preferences
      • Solder pads for the wire connector does away with the need for sourcing connectors and saves costs
  • A large cut out for the voltmeter to allow for:
    • Different tolerances for a varied meters that are out there on the market
      • The power wire to easily pass through
      • .......and for access to the tuning pot while in circuit (see below pic)
  • An elongated screw hole mount on one side of the meter to allow for:
    • Differing manufacturing tolerances for varied meters on the market
    • And, should you choose to, can use a 4-character voltmeter
  • Traces for each power rail are poured on both layers to handle the amps
  • Idiot-proof silksscreening (fingers-crossed) so one doesn't solder connectors on the wrong side
Parts needed to assemble this are:
  • 1x - Molex Mini-Fit Jr 035318062, Right Angle 6 position 0.165" (4.20mm)
    • Not needed if you don't intend to use this as an ATX-to-JVS adapter
  • 1x - Digital Voltmeter
    • Not needed if you are using this as an ATX-to-JVS adapter
  • 1x - JS203011CQN
    • Not needed if you are using this as an ATX-to-JVS adapter
  • 2x - B06P-VL
    • Only 1x is needed if using this as an ATX-to-JVS adapter
  • 2X -B08P-VL
    • Only 1x is needed if using this as an ATX-to-JVS adapter
Additionally, you'll need to crimp JVS power cables going from this PCB into the JVS PCB. So you'll need:
  • 2x - VLP-06V
  • 2x - VLP-08V
  • along with the proper pins: SVF-61T-P2.0
If you don't have handy your own modular ATX cables, you can crimp your own:
  • Here is the mating connector for the 6-position Mini-Fit Jr connector: 0039012060
  • Here are the pins: 0039000038
    • Get 2x extra of these pins so that you can build a jumper wire to ground pin 14
  • And instead of powering this off the 6-position Peripheral & SATA connectors, you can use this connector and power off the 24-position mainboard connector: 0039012240
    • Using this connector would allow you to jumper pin 14 to ground more easily
    • If pin 14 isn't grounded, ATX PSU needs another switch for enable powering
And here is the gerber file. Keep in mind this is untested at this point:


  • Gerber_JVS_PSU_Meter_Adapter_2022-04-07.zip
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And here is a pic of a voltmeter that has a tuning pot in the back. On the upper left are the solder pads for the power wire connector which were removed in this pic. The tuning pot is on the upper right. I cut off the excess solder leads on this one and rounded out the solder joints so it sits flatter and does scratch up what it mates to. I just happened to buy a bunch of these from a random eBay listing and was pleasantly surprised that it came with these pots. I can say, once turned they are very accurate to my Fluke DMMs. I think they were less than a buck each for these 3-character voltmeters.

Sorry to necropost, but has anyone built one of these yet and tested it? Just got a NAOMI and trying to figure out the best way to power it.
I know I can build it myself, I'm asking if someone actually HAS built it? The post with the gerber file states "Keep in mind this is untested at this point". Not really wanting to hook up a self-built untested designed PCB to my own equipment.