Sporniket's log on hardware stuff

[sporniket]

No idea.

At the very least, when probing, I used the spring thingy and the pointy tip to minimize the current loop, and probes were set at x10.

[sporniket]

Finally got my PCB, it's time to do a fitting session and see how it goes...

With the original PSU, before snipping the wires

2023-10-13--01-original-psu.jpg (62.91 KiB) Viewed 412 times

With my PCB and the terminal bloc fitted (the wires are pretending to be connected too)

2023-10-13--02-fitting.jpg (60.01 KiB) Viewed 412 times

My footprint for the terminal bloc is misoriented, but the good thing is that it makes it placed away from the wires connected to the plug receptacle. Also, the wire connected to 5V is just long enough to be connected to the path with the fuse. It's too short to go to the far left.
I will fix the position of the terminal block in a next iteration, but this version is good enough.

Now, I have to make time for the assembly, and prepare a small adaptor to plug the result into my electronic load...

edit : need to buy nylon washers too, for better isolation with the mounting screws.

[sporniket]

Today I was feeling like making some assembly for my prototype, and the wiring verification is ok

2023-10-22--01-assembled.jpg (101.46 KiB) Viewed 356 times

2023-10-22--02-mounted.jpg (110.82 KiB) Viewed 356 times

2023-10-22--03-wiring-is-good.jpg (173.02 KiB) Viewed 356 times

Also, I prepared an adaptator to plug into my electronic load, and made an ad-hoc load for the 12V rail :

2023-10-22--04-adaptor-to-test-loads.jpg (58.21 KiB) Viewed 356 times

2023-10-22--05-the-load-for-12V.jpg (112.46 KiB) Viewed 356 times

[sporniket]

Finally took the time to unsolder the pins of the DC step-up module to resolder them on the bottom side, it was not so straight-forward but with lot of flux and a solder braid, I could clean up the via enough to perform the modification

2023-10-28--01-dc5v-under-test.jpg (182.44 KiB) Viewed 273 times

And thus I could do some testing, varying the current to be served. I could see the effect on the 5V rails, the voltage dropping with the increase of current. Depending on the load of the 12V rail, you will be more or less tight (we want to have at least 4.5V, more is better). About the 12V rail, the voltage were at a stable 11.98V. Here are some data points :

Capture d’écran du 2023-10-28 22-05-32.png (59.87 KiB) Viewed 273 times

And the data as text :

Code: Select all

12V Load (A) = 	0,24			
==================
5V load (A)	5V Voltage (V)	ΔI	ΔV	R (Ω)
2,9	4,36			
2,5	4,51	0,4	0,149999999999999	0,374999999999999
2	4,687	0,5	0,177000000000001	0,354000000000001
1,8	4,758	0,2	0,0709999999999997	0,354999999999999
				
				
12V Load (A) = 	0,36			
==================
5V load (A)	5V Voltage (V)	ΔI	ΔV	R (Ω)
2,9	4,25			
2,1	4,525	0,8	0,275	0,34375
1,8	4,665	0,3	0,14	0,466666666666665

Anyway after that, I chilled a little with my test program :

2023-10-28--02-plug-and-play.jpg (118.7 KiB) Viewed 273 times

I had to take care so that the wire of the power adapter is kept away from the video cable, otherwise some humming is to be expected.

So the next iteration :

• I don't want to modify the step-up module, I will change the orientation of the footprint for that.
• I also have to fix the footprint and position of the block terminals.

[sporniket]

This month I finally bought the Smartboard STe, an all in one mod (Rom switcher among 4, reflashable slots, RTC, and IDE) made by Black Cat Hardware.

And now I have to install that inside my STe. First I have to prepare the computer. I replaced the ROM jumpers by some convenient right angled switches, to be able to change at will between stock and the setting required by the mod :

2023-11-11--02-jumpers-before.jpg (43.96 KiB) Viewed 202 times

2023-11-11--03-jumpers-after.jpg (46.26 KiB) Viewed 202 times

Then I have to replace at least P101, because there is no space to solder some wires on its legs from the upside. I snipped and removed the legs, but on the underside, some pads have suffered.

2023-11-11--04-P101-snipped.jpg (67.71 KiB) Viewed 202 times

2023-11-11--05-oh-no-lifted-pads.jpg (41.35 KiB) Viewed 202 times

I installed a new resistor networks with legs bended to have a lot more space to solder, and tested that I didn't broke my STe in the process. Still alive

2023-11-11--06-still-working.jpg (110.91 KiB) Viewed 202 times

So I will avoid replacing P100 too, if possible, and try to continue tomorrow.

[sporniket]

This morning, I could continue the installation a little :

Before:

2023-11-12--01-the-battle-field-of-the-day.jpg (207.59 KiB) Viewed 181 times

After:

2023-11-12--02-after-the-battle.jpg (289.96 KiB) Viewed 181 times

2023-11-12--03-close-up-P101.jpg (268.39 KiB) Viewed 181 times

[Darklord]

Looks good!

[sporniket]

Yes, so far so good. I'll post the follow up later

[tOriman]

Hi,

Nice I watch your log. Awesome activity, man...

Greetings
tOri

[sporniket]

Thanks @tOriman , your work is awesome too