Sporniket's log on hardware stuff

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sporniket
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Re: Sporniket's log on hardware stuff

Post by 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.
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sporniket
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Re: Sporniket's log on hardware stuff

Post by 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
2023-10-13--01-original-psu.jpg (62.91 KiB) Viewed 10261 times
With my PCB and the terminal bloc fitted (the wires are pretending to be connected too)
2023-10-13--02-fitting.jpg
2023-10-13--02-fitting.jpg (60.01 KiB) Viewed 10261 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.
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

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

2023-10-22--01-assembled.jpg
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2023-10-22--02-mounted.jpg
2023-10-22--02-mounted.jpg (110.82 KiB) Viewed 10205 times
2023-10-22--03-wiring-is-good.jpg
2023-10-22--03-wiring-is-good.jpg (173.02 KiB) Viewed 10205 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
2023-10-22--04-adaptor-to-test-loads.jpg (58.21 KiB) Viewed 10205 times
2023-10-22--05-the-load-for-12V.jpg
2023-10-22--05-the-load-for-12V.jpg (112.46 KiB) Viewed 10205 times
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sporniket
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Re: Sporniket's log on hardware stuff

Post by 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
2023-10-28--01-dc5v-under-test.jpg (182.44 KiB) Viewed 10122 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
Capture d’écran du 2023-10-28 22-05-32.png (59.87 KiB) Viewed 10122 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
2023-10-28--02-plug-and-play.jpg (118.7 KiB) Viewed 10122 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.
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sporniket
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Re: Sporniket's log on hardware stuff

Post by 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
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2023-11-11--03-jumpers-after.jpg
2023-11-11--03-jumpers-after.jpg (46.26 KiB) Viewed 10051 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
2023-11-11--04-P101-snipped.jpg (67.71 KiB) Viewed 10051 times
2023-11-11--05-oh-no-lifted-pads.jpg
2023-11-11--05-oh-no-lifted-pads.jpg (41.35 KiB) Viewed 10051 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
2023-11-11--06-still-working.jpg (110.91 KiB) Viewed 10051 times

So I will avoid replacing P100 too, if possible, and try to continue tomorrow.
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sporniket
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Re: Sporniket's log on hardware stuff

Post by sporniket »

This morning, I could continue the installation a little :

Before:

2023-11-12--01-the-battle-field-of-the-day.jpg
2023-11-12--01-the-battle-field-of-the-day.jpg (207.59 KiB) Viewed 10030 times

After:

2023-11-12--02-after-the-battle.jpg
2023-11-12--02-after-the-battle.jpg (289.96 KiB) Viewed 10030 times
2023-11-12--03-close-up-P101.jpg
2023-11-12--03-close-up-P101.jpg (268.39 KiB) Viewed 10030 times
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Darklord
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Re: Sporniket's log on hardware stuff

Post by Darklord »

Looks good! :dualthumbup:
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tOriman
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Re: Sporniket's log on hardware stuff

Post by tOriman »

Hi,

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

Greetings
tOri
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