DIY – Page 9 – VoltLog

Voltlog #252 – How to fix a solder bridge

Welcome to a new Voltlog, today I want to talk about solder bridges and show you how to deal with them. A solder bridge can happen for many reasons, incorrect soldering temperature, incorrect amount of solder being used, too little or no flux, or just the incorrect technique for soldering but they all basically mean the same thing , a blob of solder shorting two or more conductive surfaces on your PCB.

Modern printed circuit boards which typically get soldermask coverage even between IC pins will help prevent this problem because molten solder normally doesn’t stick to the soldermask surface and so it’s harder to form a bridge across that surface.

But even with enough experience and the proper technique solder bridges can still happen if you do hand soldering on fine pitch ICs, it’s just part of the soldering job. It’s true that as you get better at soldering they will happen less often but don’t think they go away forever. So it’s good to know how to deal with them.

Voltlog #250 – Replacing Bad 4mm Banana Plugs With High Quality Hirschmann and Staubli

In this video I replace some of my old crappy 4mm banana connectors with some new Hirschmann and Staubli, high quality connectors. These should be more reliable and provide a low resistance connection between my test gear allowing me to pass high currents without any issue.

Voltlog #249 – Making Some USB Serial Converter Boards With CH340E (part 1)

Welcome to a new video, today I’m building a bunch of usb to serial converter boards because if you are into electronics and microcontrollers you will for sure need a bunch of usb to serial converters to connect your boards to a computer for example.

The idea for building these boards started when I found the CH340E converter chip on aliexpress, I like several things about this chip, it was small because it comes in MSOP10 package, it was cheap at about $0.40 a piece and it requires minimal external circuitry, in fact it only needs an external bypass cap.

Voltlog #248 – Atorch Q7 USB Meter/Load With QI Wireless Charging

So this load is built with 3 active pcb’s as well as a fourth passive one as a front panel. They are joined with these brass standoffs and I think the standoffs act as circuit paths as well because I see no wires between the different levels. In order to get the alignment right during assembly the designer of these pcbs, made these corners rounded while these ones are diagonally cut and you can see these features along an entire side. This is a neat solution overall because it saves cost and as long as the screws are tight these should provide adequate connection.

Voltlog #246 – What if we install a heatsink on the TPS61088 boost module?

In the previous video where I took a closer look at the TPS61088, I did some measurements of the output noise but I also ran the module up to the maximum specified output power of 12V 2A. It was to be expected that the losses would turn into heat and just the small size of the board would not be enough to dissipate all that heat safely so the boost chip reached a toasty 150 degrees Celsius and inevitably went into thermal protection.

There were two questions that people mainly left in the comments of that video. First people were curious if this module would behave differently if a heatsink was installed and also some people thought about using this module in a fixed configuration, because if you remember there is a chip on this module that will switch the output voltage based on quick charge spec, depending on what the load is requesting through that protocol but people might just want a simple fixed output. To this I would add a third question of my own, what is the real efficiency figure of this module, at the maximum output.

Voltlog #245 – TPS61088 Boost Module Test (with QC3.0)

The real limitation for this small module to output the claimed 24W for longer periods of time is temperature. There is not enough thermal dissipation happening with this small pcb. Having a bigger pcb with more copper layers would help and it would probably allow this module to output continuously and prevent the TI controller chip from going into thermal overload. Even so I was impressed that running it into thermal protection several times did not do any damage the chip recovered on it’s own each time and no magic smoke escaped during these tests.

So all of this considered, this is probably one of the best dc-dc boost converter modules I got from China so far and I would recommend getting one of these if the specs meet your needs.

Voltlog #243 – TS80 VS KSGER T12 Soldering Iron Comparison

Welcome to a new Voltlog, yet another soldering iron comparison video and today it’s between the TS80 and the KSGER T12 station. Everyone knows the TS80, is quite a popular portable soldering iron, works with USB type C input, it needs a quick charge compatible adapter to reach full power and it’s quite a capable soldering iron. The drawback is the cost of the tips, it uses this proprietary type of tip and the cost is about $20 a piece.

On the other hand we have the KSGER soldering station which I reviewed in Voltlog #232. This station has a built in power supply and uses the well known T12 tips which are widely available on aliexpress, for example you can get KSGER T12 branded tips for about $3 a piece. I think that’s important, because I have 2-3 different tip shapes that I use regularly and maybe another 2 or 3 that I use occasionally for odd jobs. You can’t just rely on a single tip shape and purchasing the same number of tips for the TS80, is not going to be cheap.

Voltlog #240 – ESP32 PIR Motion Sensor With Deep Sleep & MQTT

Welcome to a new Voltlog, in this video I’m gonna show you how I designed and built this board which functions as an esp32 based, battery powered PIR motion sensor. So I started by designing the circuit, I used some common building blocks, I added the ESP32 with it’s bypass caps, some test points and the programming circuit with auto-reset, I then added some connection points for the PIR sensor, an RGB LED because why not have a nice way to signal this is one of those very small digital RGB leds, it’s just 20x20mm, it’s connected to 3.3V even though it’s only rated for 5V so I’m hoping this is going to work even on 3.3, it’s also worth having a temperature/humidity sensor to also sense that in whichever room the node will be placed and finally the power supply circuit which is a simple low dropout regulator with an 18650 battery as the input.

I did not include a battery charger circuit on this module, because I wanted to keep things simple, I’ll have a battery socket so I can just remove the 18650 cell and charge it separately plus the whole circuit should run in sleep for extended periods of time giving me a long operating time so i wouldn’t have to charge the battery too often.

Once the schematic was finished I did the board layout in a hurry so it’s not exactly pretty or optimized

but I tried to move the esp32 antenna to the side, to place the PIR sensor in the top side as the module will probably sit vertically, I tried to place the temperature sensor in the bottom side to keep it away from any components that might get hot and also placed some isolation slots for the same reason.

You should check-out revB of this board, I made some improvements present in the video below.

Voltlog #239 – Upgrading The CR10 3D Printer With New Print Surface And Bed Insulation

Welcome to a new voltlog, it’s time for another upgrade on my Creality CR10 3D printer, and this time it’s about the print surface. By default this printer comes with a glass print surface which sits on top of the aluminium bed and that has worked fine for most prints and settings I’ve tried but occasionally I would get some adhesion problems and with glass you need to wait until the part has cooled down in order to remove it. Not such a big deal but there is this newer magnetic print surface, which has two parts, you get the bottom part with adhesive that you stick to the aluminium build plate of the printer and you get the top part which sticks magnetically to the other part.

This way, with the top surface I should get better adhesion and when the print is finished I can just remove the print surface from the printer to have it cool down faster or maybe for easier removal because I could just bend the surface to cause the part to unstick.

I’m also going to upgrade the bottom heater of the bed by installing one of these insulation sheets, this should help it reach working temperature faster and maybe it will use less power to keep it at working temperature.

Voltlog #238 – Finally Printing Shrink Tube Labels With A Brother Printer

As shown in the previous video I had to trick the printer to accept this type of cartridge by masking some of the micro switches it uses to detect the type of cartridge but that solved one problem and created another one. The text was now mirrored because that works out for regular label tape which gets printed on the inside of a transparent film. However for heatshrink where the label gets printed directly on the tube, it will end up reversed.

I’ve only tried one combination with the 3 micro-switches but some people suggested in the comments that I should try other switch combination and boy were they right because I did find another switch combination which causes the printer to accept the cartridge and mirror the text as well. So this is the right combination to use with my type of printer and this type of cartridge. The two bottom holes need to be opened, and only the single top hole needs to be covered. You can use a small piece of kapton tape like I did here.