My Ultimate Multi Power Module – Part 3
com, and how nice that you want to follow along with this project, Building my Ultimate Multi Power Module.. This is part three in which were gon na finally build everything, together. So Ill. Let you take a look over my shoulder in designing and printing a case for the module and the PCBs that are gon na make this module.. This is my Zauberling.. I hope you remember it from a previous video.. Take a look at my timeline there. And because the installation space is ultimately only three and a half by seven centimeters. I had to split the printed circuit board into two layers that can be sandwiched together., Like so.. Designing a PCB sandwich like this is always a great challenge, because the gap is only 11 millimeters and you have to make sure that parts on the bottom of the top PCB do not collide with high parts on the bottom PCB. For this project. I also need a relay like this.. The problem here is that this single component is already higher than 11 millimeters, But I think we can tackle that by just lowering those small rims at the bottom of the casing. A little bit. About one millimeter will do the trick., So we can gain that extra height in between the PCBs without having to raise the front or such.. Another thing is these voltage regulators.? There are two well big voltage: regulators. The rest is SMD type on the PCB. And because they might develop a little heat in one of my earlier prototypes of the Zauberling I solved it like this.
. I mounted them on the back of the casing, with a little heatsink.. This new power module, however, does not need an external I2C bus connector on the back., And the programming port does not have to be as easily accessible as on the Zauberling.. After all, the firmware will not change very often., So these holes are not there.. That leaves us space for the two voltage regulators. If there was an opening they could poke through, we could even attach a passive heatsink at the back of the module to cool them.. If that would be necessary., Even if they dont develop any heat, it would always be good to have them outside the casing. Wouldnt. It Eventually Id like to have a easy, accessible on off switch and a DC connector in the box in the casing.. So we have to consider this while designing the lower PCB thats in there., Because these elements are protruding a little bit into the casing and we have to take that into account when were gon na design. The PCBs., But first lets take a look at the casing.. Here we have our original Zauberling casing and because this is a power supply module, it will mostly be used at the far left of a series of Silberlingen or Zauberlingen., So it will be the left most module in a row.. This means that this site is available for connecting the DC adapter and the easy accessible on off button of course.
. So we have to make a flat side on this side. And once we have it, we can easily digitally drill the hole for the switch. For the on off switch. And we can drill a hole in the 3D print for a DC connector.. So we have two new holes and two existing holes.. These are the 12 volt outputs at the back. Lets drill a new hole for those two voltage, regulators there. And perhaps insert a well kind of a rim to rest their heatsinks against. Like so., So the metal parts of those voltage regulators can rest against that and Leave the back of the module completely even for a possible heatsink.. Okay, there we have it in wireframe. Hope you can see what my idea would be. Hope it works out in the 3D. Print. Well see that in a moment.. So after a little work in KiCad, I came to this for my bottom PCB PCB number one., The one thats on the bottom of the case and contains the INA current sensor and the voltage regulators.. It was quite a challenge to position everything in such a way that it doesnt collide with the elements on the top circuit board or the switch or the plug that protrude inside the case.. Here we are in KiCads routing module. And, as you can see, I used quite a few vias to to get it designed. And I deliberately kept the track width of the tracks of the output voltages as wide as possible.
. Here they are one and a half millimeters. That should easily handle up to two amps. I guess. For now Ive simply opted for one ounce of copper, but you can increase this to two ounces. Or you can keep the traces open in your solder mask so that you can completely tin them in with solder.. None of this is necessary for the currents that I expect with my experiments., A quick look at the top PCB The one containing all the buttons and all the front elements like the voltage rails, the display and, of course, the microprocessor., The Arduino Pro Mini on the Back., These are the power rails for 12, 9, 5 and 3.3 volts., And there are a few LEDs on there. That signal which mode is displayed on the display. And five positions for the smd style, push buttons. I have to solder on.. There is a LED for the automatic fuse., An FTDI connector, to program our Arduino Pro Mini.. We have connectors.. This is the main power rail with all the voltages that go to the front.. We have a critical and a fuse connection.. Of course, the I2C. – And this is where the nine volts come in – and the five volts made by the Arduino Pro Mini voltage regulator go out to the bottom PCB.. Okay, so lets take a look at my freshly designed and printed 3D casing with a thickening ring for the DC connector there. It will let it protrude a little bit more outside.
, And here we have our window for two voltage regulators with a small yeah. What we call it …, a small threshold to lean against., Leaving the back completely flat.. I think this gon na work., Because its completely flat, we can attach a passive heatsink. Like so. And with the DC connector. This little ring will save us a few millimeters inside the casing.. There is room on the PCB to accommodate thisswitch., So there you have it a new incarnation of the Zauberling casing with a flat side. So after a bit of waiting, I got this. My printed circuit boards. This is the lower PCB, with almost all the SMD components already placed.. So all I have to do is place some through hole, components to really finish it.. Unfortunately, there was a mistake made by me.. I mistakenly removed one of the components from the Bill of materials.. The 3.3 volt voltage regulator is missing here.. So I have to hot air solder that in myself. – And there is another thing. – I have to make a connection. Here., Unfortunately, two of the vias are missing.. Look at this isolated trace. That has no vias.. There must be vias inserted here, just like the ones over here. And they are in fact placed by me in KiCad, but they didnt show up in the drill file. So I have no clue how that happened. Im recommended for any tips. If some of you know why this apparently happens.
So lets, take a look at the top PCB., Not much going on there.. I have to hold air solder some resistors for LEDs on there.. Four of them. And the rest of it can be quite easily. Semi smd mounted, like this Arduino Pro Mini board on the bottom of this small PCB.. So just take a look at my Zauberling video down my timeline here to learn more about this height saving mounting method. Is that a word I hope so? Okay were all done.. This is my lower PCB with my fixed connection and my soldered voltage regulator over there. And the rest of the components is already mounted.. I omitted the fuse and the switch., And also the DC plug, is not soldered on there yet., But this gives a good view of the INA chip with its shunt resistors.. We have our connectors soldered on, so everything is in place to give this pcb a little test drive.. This is our I2C bus.. So to test this little thing, we could do exactly the same. We did with the breadboardtesting. Ive got my voltage regulator in place for the moment., So five volt has been produced for the INA chip and we dont need the top PCB yet.. Let me connect this thing.. First of all, our 3.3 volt is coming out here on the first and the second one. Yeah, very nice., Five volt for that one. And we have nine volts over here., And this is just the DC input voltage of around 12 volt.
Voltage. Regulators on the back. Theyll be poking through the bottom of the case in a moment. Once we have built in this little pcb theyll be sticking out at the back. Lets, see and check this.. This nine volt coming in our temporary voltage regulator and five volts going out., So the INA chip must also be powered up with the correct five volts.. Let me see if we can read it … And hey presto. It worked right away and when we pull the yellow I2C bus like so it just reads: zeros. Thats one of the characteristics., An unconnected I2C bus, just returns zeros, which is different from a completely not powered up INA chip., Because when we pull our temporary voltage regulator. Here and omits the five volts to the INA chip: you see that it hangs. And it just goes on when we put it back and give it 5 volts. Again.. Okay, lets take a look then, at the top PCB with the front elements. Arduino Pro Mini hanging. There on the bottom. Piggyback style. And on the front, of course, all the elements that we want to bring through the front.. This small custom printed 3D stub goes underneath the display to mount that to the correct height. Over there., And i hope it will fit. Lets see if it fits …. Of course, i already tried it out Thhere he goes. And by the way I already flashed the Sketch into this top PCB.
So we can immediately test it.. As you can see, there is a little gap because the relay is a bit toohigh.. There is a small gap in the connectors here., No problem, because weve sinked the bottom PCB a little bit more into the case.. So nothing happens on the front there in terms of height. And as you can see, theres little room., So its very crowded there.. But it all fits very snugly into the tiny space within the casing., So were quite efficiently using the height and all the space that we have in the case. I just cant wait to test it.. It is initializing its screen as you can see., And there it is. Its displaying the first voltage on its display, which is the external 12 volt., And we can go to the next step, which is displaying the 9 and the 5 volts.. Of course, the 3.3 is not displayed, but we can have everything on one display. And we can reset the whole module.. I hope you can see the little blinking LED signals, a initialization phase for the relay and the automatic fuse. Like so.. So this is fully functional. And well there. We have it. One comprehensive module, providing 12 9 5 and 3.3 volt Lets see. If all these voltages are really there.. This must be the 12 volt input. There. You have it. And this 12 volt coming from the external DC adapter.. Of course, that is also passed to the back of the module, so you can loop it through to your other Silberlingen or Zauberlingen.
. Yes, thats, okay And while I go on testing the other voltages, this is a great time for you to subscribe to my channel. Should you like these videos, or should these videos be of any use to you with your own electronic projects. Next step, Building it all in.? So, as you can see, Ive already inserted the two voltage regulators in their window in the bottom of the casing., And there goes the lower pcb. It fits nicely into the box., The two 12 volts connectors protruding through the bottom. There, you go. Voltage regulators on the back completely flush. With the surface of the back of the modules.. An external heatsink is optional of course.. As you can see, I already have the DC connector and the switch in place. And Ive connected and soldered the sides strips of the module. Were almost there. Just by inserting this pcb this top PCB. With all the front elements on it, we are almost ready to test.. Let me show you my laminated and 3D printed front. Here. Heres one Ive prepared earlier. Always wanted to say that, And it just fits over the front elements on the top PCB like so. Lets. Connect some power and see if it works well. It looks like it. There he goes. Displaying the different voltages. We can cycle through the display. And before we conclude this final part, three of this video series lets give it a test with the motor again Automatic fuse Of 12 volt kicks in at one and a half amp at the moment.
Lets lower that a little bit under 100 milliamps and see if it really works. If we hold the motor., For instance, 80 milliamps will do. Ill hold the motor … And there it goes. The automatic fuse trips., So thats tested and everything seemed to work very nice.. So this concludes my quest for my Ultimate Multi Power Module Its great that you have watched the development of this useful module so far, Youll find all the information in the comments of this video. And if you like it subscribe to my channel Im looking forward to Seeing you with my next project. Until then …