Tag: voltlog

Uni-T UT501A Insulation Tester Review & Teardown – Voltlog #372

Welcome to a new Voltlog, for today I’m going to review & teardown this Uni-T Insulation Tester, the model number is UT501A. We’re going to start with a general introduction and then continue with a teardown and presenting some real world test scenarios. If at any point you are interested in ordering one, please check out the links I’ve placed in the description below.

So, like the name implies, this meter is good for testing insulation resistance but why would you need to do that? Well you would want to test the insulation resistance of a particular circuit or piece of machinery immediately after first installation or repair or through its service life to discover potential problems before they occur.

Let’s take for example the winding of a motor, every turn of copper wire is insulated but because of stress, harsh operating environment, over time, the insulation might start to fail and by testing regularly you can start to nice if the insulation resistance starts to drop and you might be able to service that piece of equipment before catastrophic failure.

Or another good example is when you wire up the electrical installation for a new home. During the installation procedure or during the construction period, accidental damage might occur to the wiring so it’s good practice to test for insulation resistance before you start using the new installation.

Pokit Meter Review – Voltlog #371

This is a bluetooth pocket multimeter which means it doesn’t have a display, it uses a smartphone/tablet app to display the measured data and it can do almost everything that a basic meter does: it can measure ac/dc voltage but no true RMS capability on this model, ac/dc current, resistance, continuity, diodes and as a bonus it can also do data logging and it has an oscilloscope mode but with a more limited range of values & functionality given its size. I find this pretty cool, because they managed to build so many functions inside such a small package like I have not seen pocket multimeters that can do data logging so far.

Right from the start you realize why they call it a pokit meter, it’s basically the size of a small puck, less than 5cm in diameter and about 17mm thick. Inside the box you get the meter itself, a pair of J-clips, a spare fuse, a small neoprene carry case and a quick starting guide. The first thing you need to do is to remove the battery seal and you have to twist the battery cap for release and then pull on the small insulating paper which then activates the CR2032 battery.

Start Hacking The CAN Bus With The ESP32 CanLite Board – Voltlog #370

Welcome to a new Voltlog project video, today I’m gonna be presenting this little guy called ESP32 CanLite. This is a CAN hacking / development board based on an ESP32 and this is the results of my adventures into hacking the CAN network on my vw golf. I have not made any significant progress on the actual task of hacking the can bus other than what’s shown in Voltlog #342 simply because I got very busy with the professional work I do, consulting for various clients, you know just designing and building electronics but nonetheless I found the time to design and refine this board because this is already the second revision.

InTheMail | Voltlog #369

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time and I must say that I’m worried about the future of mailbag videos given the new EU regulations on imports from China which are going into effect starting 1st of July here in Romania, I’ll have to do a separate rant video on the subject but there might not be any mailbag videos going forward.

I’m gonna start with this mailbag with a brand that you are already familiar with here on the channel, it’s difficult for me to pronounce this, I don’t know how it should be pronounced but these guys make affordable adhesives and related products. I haven’t had this one before, it’s the first time I’m getting the Kafuter K-5203 which is a thermal adhesive and to be more specific, their description is reinforced thermally conductive silicone elastomer with great adhesion, insulation and dissipation. And to give you some numbers they claim it can withstand variations of temperature between -60°c and +280°c and it has a shear strength of 30kg/cm3. The thermal conductivity is 1.2 watts per meter kelvin. I don’t need to tell you how to use this, it’s good for attaching stuff to a heatsink, in general stuff that also needs some form of bonding to the heatsink.

I Made A 10 Channel Thermocouple Data Logger – Voltlog #368

The idea for this project started when I got the T-962 reflow oven, after running a few tests I discovered that it had some hot-spots which meant some areas inside the oven were hotter than others and this could lead to trouble, you could get melted connectors in some places and cold joints in other places. Now it’s hard to tell how bad the situation is without doing some measurements so I decided to design & build this board which is capable of reading 10 thermocouples and logging the data. This way I could place the thermocouples inside the oven, something like a 3×3 or 4x2x2 matrix and I could get a sense of what’s going on inside the oven.

New Lab, New Voltlog Electronics Workbench | Voltlog #367

The most important part of this lab is obviously the workbench and this is something that I designed myself, I guess I can call this the Voltlog Workbench Design, it’s 2m wide with 80cm deep. The working surface comes out at about 95 cm from the floor. It sits on these adjustable feet but I haven’t even leveled it so far. Thanks to my friends at Welectron.com my working surface is protected with these nice premium ESD Mats. They are 100% and phthalates free, no bad smell, Heat and solder resistant, Chemical resistant, two layer ESD bottom side is conductive, top side is dissipative and they have this nice anti-reflective surface finish which is very comfortable to work on. I went with gray because it works best as a background for video shooting but you can opt for Blue as well. I’ll put a link to these in the description below, I highly recommend Welectron for their services & customer care and I highly recommend these ESD mats they are top quality.

InTheMail | Voltlog #366

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. I’m gonna start with this EVA hard carry case, it has a rather strange shape but, this will fit one of these budget label printers perfectly. And if you are like me, using the label printer in the lab, where everything is clean, it might be perfectly fine to just keep it in a drawer but at some point a friend asked for my help to figure out the networking wires in a building, basically to identify every wire, crimp it and install some networking gear. Well when you start doing stuff like that you need a carry case for your label printer because it’s gonna get dirty, there will be dust and grime and the LCD might get scratched, you might want to toss this into your tools bag so that’s when I decided to order one of these hard carry cases, they’re fairly inexpensive so well worth getting one.A higher price printer might get one by default from the manufacturer but for these discount $30 printers you can’t really expect to get one from the manufacturer so you need to order it separately.

Upcoming Projects Teaser – Voltlog #365

Welcome to a new Voltlog, for today’s video I want to share with you some of the projects I currently have on my workbench, these are projects that still need some work to be done before they can be published but this will give you a glimpse of what to expect in the upcoming weeks on the channel.

I have these 3 projects on my workbench, the first one is a multi channel thermocouple data logger device based on an ESP32. This has 10 channels based on the famous maxim thermocouple interfacing chips and all of those are read by the ESP32 and data can be logged on an SD card. This should help me measure the temperature inside the T962 reflow oven that I reviewed a while ago in a grid to check how the heat is distributed inside the oven. I’m pretty sure there are some hotspots inside the oven and some cold spots, I don’t know if there is anything I can do at mechanical/design level to correct for them but it would sure be nice to be able to know what’s going on inside the oven and with such a board I can just connect 10 of these cheap braided K-type thermocouples from aliexpress and hopefully get some consistent readings but more on this in a future video.

The next one is an FT2232 based interface which I designed with the main purpose of allowing me to interface via JTAG to FPGA boards. The chip itself is capable of other protocols as well but my goal here is like I said to interface to various FPGA boards. I plan to dip my toes into the FPGA world and try to get a blinky up and running on an FPGA board for a start. I have designed the board to include a voltage level translator because the chip is running at 3.3V but whatever you connect this to might be running at 1.8 or 2.5V so there is provision for that and it uses USB Type-C like all of the boards that I’ve designed in the past year.

The third project is an ESP32 based CAN development board that I plan to use in my adventures of hacking the CAN bus on my car. I should be able to install this into my car to intercept, modify or send CAN messages while at the same time having two outputs which I can use to control various stuff with on/off 12V power. It has a dc-dc converter on board to step down the car 12V to 3.3V to power the board and if I remember correctly the chip was chosen to have a wide input voltage range to accommodate for any potential spikes on the 12V rail of the car.

How To Create High Voltage Isolation Slots In Kicad – Voltlog #364

Back when I published the video on the aquarium controller I built, someone asked how are these high voltage isolation slots or cutouts done in Kicad and I thought I’d do a short video to explain how you can design these into your next project but first, let’s talk about their purpose and whether or not you need them.

There is a common confusion between the terms creepage and clearance, myself I’m guilty of sometimes making this confusion but to give you a clear view on this, I found this picture online which shows everything very clear. Spacing between conductive elements through air is clearance while Creepage is spacing between conductive elements over an insulating surface.

By adding these cutouts in the PCB we are only increasing creepage distance, but if you would also like to increase clearance you will need to add some kind of barrier, and this is usually built into the enclosure and it will slide through the slot creating a barrier to prevent any potential high voltage arc to jump over the barrier by increasing the length.

There are also secondary purposes for putting cutouts into your PCB, I have used them in the past to create a thermal barrier or to accommodate various enclosure walls and features but I won’t talk about those today, those applications tend to vary a lot on a case by case basis.

But if you are using them as high voltage isolation you need to be aware of some aspects: first and most important remember to make the slot at least 1mm wide, if possible go with 2mm as this is required by some standards. There is a min width required by the fab house anyway because they are going to use a router bit on a CNC machine to cut that slot into the PCB and this may vary from one board house to another but I’ve seen 0.8mm mentioned by most PCB manufacturers. For example PCBway which is the sponsor of the channel, gives a min value of 0.8mm non plated slot and 0.5mm for plated ones. For isolation purposes you only want non plated ones.

There might also be other limitations on the size of the corner radius, I’ve not hit any of those so far myself but just imagine that router bit going around, it will not be possible to create very small features at your request.

InTheMail | Voltlog #363

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. I’m gonna start with this little board which is an ethernet shield type of module which can bring TCP/IP connectivity to your project via a SPI bus. So this could mean any microcontroller that is able to talk over SPI to this chip can become internet connected. Now ofcourse these days the ESP32 is pretty popular, everyone is using wifi but for the highest reliability in network, wired connections are still preferred and there are also other microcontrollers that do not have a built-in ethernet interface so you need to add it externally with something like this. It’s fairly inexpensive so I think it’s worth keeping one of these around however interfacing to it might not be as trivial so it’s best to stick to the platforms that already have libraries written for this chip, like Arduino. Same as always, you will find a link to this in the description below the video.