Board PCB

Assembly instructions for our limited edition OXO board
jmmcg
Posts: 52
Joined: Sat Apr 11, 2020 2:45 pm

Re: Board PCB

Post by jmmcg »

This is the first surface-mount kit I have ever assembled, so apologies for my ham-fistedness! (The OXO kit was a present from a good friend, Robin.)
I have assembled the base-board and two of the NIXIE driver PCBs. I tried two IN-7s in the boards & neither struck. I presume I have faultily assembled the (black, surface-mount) base-board.
When I assembled it, the drive current seemed to increase as suggested in step
I presume the pads are driven in parallel, so if none are working then my error should be in an area common to all the pads.
1. Can you confirm the approximate voltages (peak-to-peak) & frequency for the inputs to the driver pads. (I am considering buying a very cheap oscilloscope to verify the signals & want to make sure it has the required performance.)
2. I presume the IC creates the signal to drive the pads? If so, can you confirm the voltages on significant pins?
3. Are there any other useful probe points to indicate what I might have done incorrectly?
Thanks a lot!
jmmcg
Posts: 52
Joined: Sat Apr 11, 2020 2:45 pm

Re: Board PCB

Post by jmmcg »

jmmcg wrote:This is the first surface-mount kit I have ever assembled, so apologies for my ham-fistedness! (The OXO kit was a present from a good friend, Robin.)
I have assembled the base-board and two of the NIXIE driver PCBs. I tried two IN-7s in the boards & neither struck. I presume I have faultily assembled the (black, surface-mount) base-board.
XXXsnipXXX
3. Are there any other useful probe points to indicate what I might have done incorrectly?
Thanks a lot!
I have it working! I put the wrong component in R2: bridged it as per instructions and all the pads work well! Thanks for your understanding.
Tony
Site Admin
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Joined: Tue Jul 24, 2012 8:05 pm

Re: Board PCB

Post by Tony »

Pleased to hear that.
For future faultfinding, yes the IC provides the drive signal but each pad has its own driver transistor or there would be too much variation when pieces were removed.
R2 was intended as a dropper if the supply voltage ended up being more than 5V, in this version it didn't so isn't needed, the PIC can be connected directly to the incoming supply.
jmmcg
Posts: 52
Joined: Sat Apr 11, 2020 2:45 pm

Re: Board PCB

Post by jmmcg »

Tony wrote:Pleased to hear that.
XXXsnipXXX
Thanks!
jmmcg
Posts: 52
Joined: Sat Apr 11, 2020 2:45 pm

Re: Board PCB

Post by jmmcg »

FYI a photo of the pad waveform on the baseboard. Note the voltage is 10x (as I used a x10 probe). Many harmonics.
Attachments
Pad waveform.
Pad waveform.
waveform.jpg (202.58 KiB) Viewed 6531 times
Base board pad waveform.
Base board pad waveform.
base board pad waveform 1.JPG (238.01 KiB) Viewed 6588 times
jmmcg
Posts: 52
Joined: Sat Apr 11, 2020 2:45 pm

Re: Board PCB

Post by jmmcg »

I replaced the 5mm power socket with a micro USB C socket for greater power-supply flexibility. (USB v3.0 can supply the current.) Sadly I thought too late to add a "TP4056 Lithium Charger Module with Battery Protection, Micro USB 5V 1A" plus a Li-Ion battery (Part No. PD2280100 from https://www.batterylipo.com/lipo-battery/) to make the OXO game truly portable! (It could fit under the main board in the ~2mm space available.)
Tony
Site Admin
Posts: 951
Joined: Tue Jul 24, 2012 8:05 pm

Re: Board PCB

Post by Tony »

That would be well worth doing - I've wanted to make a couple of battery-powered devices but there are so many safety issues posting and using lithium battery packs, one reason the clocks use a backup capacitor is to avoid the inevitable 'does it contain batteries' question at the post office..
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