exxos's Atari, Amiga & retro forum

I'll start here a little blog about electronic stuff, but nothing to do with retro stuff.

For this first post, here is a contraption I made after my little one (8 and half y.o.) laid out some LEDs and some push button. Then she told me what it has to do.


So, there is one yellow push button to switch on, one yellow to switch off, the blue/green/red push button should trigger an animation of the led (only the green leds are done). I will post the schematic later (work in progress).

The double push-button on-off is done with two transistors (one NPN, one PNP), the clock is generated with a '555, and the LED chase is using a CD4015 (dual 4bits shift registers). This is the circuit that made me realized that I had forgotten a pull-down on the data input line triggered by a pushbutton.

Done the schematics of this "triple led chaser"


the project is here : https://github.com/sporniket/triple-tri ... -mainboard

next step is making a pcb

I think this will need a video once it's all completed!

Looks like a great way to engage our children in our hobbies!

:thumbup:

JezC wrote: 17 Mar 2022 11:26 I think this will need a video once it's all completed!

good suggestion :)

JezC wrote: 17 Mar 2022 11:26 Looks like a great way to engage our children in our hobbies!

Absolutely !

lol. This is great!

Maybe we can rope your daughter into helping with the twin shifter revisions! :lol:

:D

A little update : added a missing capacitor, some bypass capacitors, mounting holes ; and the routing is done.

Waiting next month to order pcbs (including the respin of the "Twin Shifter"), I am reworking my electronic board project (started around https://www.exxosforum.co.uk/forum/viewt ... 120#p72944 )

It turns out that soldering the heatsink on the PCB is just not doable, even with my 80W soldering iron. Well I had carefully selected that heatsink for its quite low thermal resistance... :D

So, going back to square one, I will use small heatsinks screwed on each mosfet, and spread the load among a "mosfet grove" (I provision space for up to 16 mosfets, so that the current through each mosfet could be down to 1/4A for a total current of 4A). And deciding that a separated module for the power sink and one to bridge between the sink an a microcontroller is likely to be cumbersome.

My little "mosfet grove" seems good to me.

And now a first variant ("lite") my latest design, loosely related to retro stuff, one of the reason I need an electronic load, dubbed "Delivery Of Power" (DOP) as an obvious wink to USB Power Delivery. So this "lite" version aims to use the 5V×3A to get a 12V rail with up to 0.5 amps, and the remaining power to the 5V rail.

The github repository : https://github.com/sporniket/dop-lite

It should power a stock H5 (with not too much add-on) with the legacy DIN-13 video port to a color TV. If one don't need the 12V, it should be able to power the H5 with some more little add-ons.

On a stock legacy ST(e), all should go well until one use the serial port too, I sense that it could be a little bit too much.

The PCB is 5×5 cm.


Since this is the "lite" version, there will be a "regular" (4-4.5A on the 5V rail, 1A on the 12V rail), and maybe a "heavy" one (up to 6-7A on the 5V rail)