Welcome to a new Voltlog, this will be a rather short video where I will be talking about a rather common subject, LEDs. I’m sure everyone uses them in their projects but if you are like me you probably never cared about the efficiency of the LEDs you use for signaling the status of something on your microcontroller board. So what I was doing most of the time was picking the least expensive LED available while still picking a known manufacturer like Kingbright or Lite-on or Osram just to avoid quality issues. And that was my voltage rail indicator LED or my blinky LED for signaling some status. But this ofcourse meant I needed to drive those LEDs with a fairly high current of 15-20mA to get decent brightness out of them and that might be OK for numerous applications but in this video i want to talk about high efficiency LEDs and how your project could be nicer because of them.
Category: Soldering
ESP32 Aquarium Terrarium Controller – Voltlog #361
This project started when a friend of mine which has a snake terrarium asked for my help to build a system that is capable of regulating temperature and humidity so the snake can live in optimum conditions. I’m not necessarily a snake lover, I would rather stay away from these kinds of creatures but that doesn’t stop me from helping my friend.
I started by figuring out what he uses to control temperature and humidity and it turns out there is some sort of a lamp to provide heat from above, some sort of mains powered stone that heats up and a water fountain, probably one that runs with fog to control the humidity. All of these are mains powered and only need simple on/off control which makes things simple when designing the electronics board.
In terms of digital control I figured it would be nice to have to be able to update the set points and check on the status values wirelessly so I went with an ESP32 modules. This also helps to add an extra layer of protection to keep the user away from the dangerous mains voltages present on the relays. I can have the whole board, enclosed in a plastic box so the user never goes near the mains voltages.
Best Technique For Soldering & Inspecting BGA Chips – Voltlog #352
Welcome to a new Voltlog, in this video I’m gonna show you my method of soldering BGA chips because in the previous video where I showed the eMMC to microSD card adapter PCB I mentioned I don’t use any stencil for soldering the WFBGA153 package. I’m also gonna be showing you a method for easily checking if the BGA chip is soldered correctly or not.
So let’s start by talking about the BGA package that I used in this project, it’s the WFBGA153, this package has 153 lead-free balls, each is 0.3mm diameter and the pitch between balls is 0.5mm. Now the footprint that I used has 0.35mm pads for each of these balls, which means that when you consider the 0.5mm pitch, in between pads you are left with just 0.15mm which is roughly 6 mil, you basically can’t route any tracks in there using any of the standard PCB services.
eMMC Flash Memory To microSD Card Adapter – Voltlog #351
Welcome to a new Voltlog, today we’ll be talking about eMMC memory chips and how you can use them in your next project and whether or not they provide any advantage over a more traditional sd card.
So historically MMC memory was first and then SD memory cards were developed based on MMC specification but added new features. Both technologies are based on some form of flash memory and they both contain a controller in the same package with the memory. Electrically it’s the same interface for both in most cases however software-wise SD card ads some new features which are not supported in the MMC standard. While standard MMC comes in a card form similar to how SD memory cards are, eMMC stands for embedded MMC and it comes in a BGA package.
The purpose of eMMC is to be used as non-volatile storage in embedded devices and almost all mobile phones and tablets used this form of flash for main storage up to 2016, when UFS started to become more popular.
Best BST-933B JBC Clone Soldering Station Review & Teardown | Voltlog #340
Soldering tools is a big subject as there is no electronics bench or hobby without a soldering iron hence why I have several videos on the subject and why I will continue to do such videos when new tools are presented. Everyone knows and probably wishes for a JCB or Metcal station since they are very well known in the industry, they are reliable and most importantly very capable soldering stations but their price tag keeps them out of reach for the average hobbyist.
That’s why clones of the big names appear on the market and they can be bought for half the price of the original one, sometimes even less. That’s why the KSGER T12 soldering stations are so popular and why I use them. They support the original Hakko tips and so they provide identical performance to a Hakko station as long as you install a good quality T12 tip.
Which brings us to the subject of this video, this is the Best 933B, which is a clone of the JBC CD-B series compact soldering station. This has been on the market for a while but I recently got a chance to review this station when banggood offered to send me one for free. I would appreciate it if you would check out the links I place in the description, this will ensure I can get more gear to review in the future. Price wise, if you were to order one of these it would cost you about half the price of the original JBC station. Depending on where you order the original one is around 400EUR while the Best station is about 200EUR on banggood.
T-962 Reflow Oven Custom Profile Calculator | Voltlog #339
In the last video I showed you how I upgraded the T-962 oven to fix some of the issues that were present on this oven. I also mentioned that there is an option to configure a custom reflow profile with this oven and that’s probably something you’re gonna have to use sooner or later because there are so many options of solder paste on the market and not only that but also there is variation between different ovens so it’s likely you’re gonna have to tweak that.
So in this video I’m gonna show you how to define a custom reflow profile in the open source unified engineering firmware. Before doing any actual configuration on the oven you need to start with the specs of your solder paste. For this example let’s assume we are working with the NP545 series from Kester, we need the datasheet of this product to check out the recommended reflow profile. Inside the datasheet we can find the recommended graph, it’s an unusually small one for this paste but luckily we can zoom in and increase the size of the graph.
At this point I recommend you grab a screenshot of this profile and import it into your favorite img editing tool because we need to draw some lines on this graph to extract some values. First I added a scale on the Y axis with a line at each 5 points. Then I added these lines to plot the absolute values on the Y axis. So we now have a set of temperature values for every 30 seconds of the profile but the firmware on the oven, the procedure for inputting a custom reflow profile expects data points every 10 seconds so we need to somehow extrapolate our values to generate more points in between.
T-962 Reflow Oven Upgrades & Fixes | Voltlog #338
This is the famous T962 reflow oven coming from China, you might find it under a bunch of different brands, it’s available to order directly from China but also from a bunch of local distributors who are importing these ovens but in general they all have this list of problems which can be easily addressed for improving the performance as well as the safety aspects of operating one of these.
I got mine for about $180 shipped from Germany so there was no tax involved and it got here pretty quickly but you can probably find it for less if you are willing to wait a bit longer and get it from China. I used to run my own reflow oven based on a toaster oven but trust me, unless you invest in a really expensive toaster oven you’re not going to get the same performance as with one of these dedicated ovens. They’re not perfect as I’m gonna show next, they still have a bunch of problems but once we address those problems it becomes a decent oven with superior performance when compared to a toaster oven.
So let’s start with the paper tape insulation problem. This oven uses glass wool for insulation of the hot chamber and to seal that they used a combination of aluminium tape and paper tape, it really looks like the cheap painters tape. Now obviously the insides of this oven are gonna get hot and that paper tape is gonna start to burn and it will release fumes and a nasty smell. If you buy this oven and start using it right away without implementing this fix, you will need to vent that room most certainly.
Luckily this is an easy fix, the only thing you need is kapton tape. The idea here is to equip yourself with a pair of gloves and place the oven on a table that you can wipe clean when you’re finished to avoid contamination with the fine particles released by the glass wool. It’s best if you have some genuine kapton tape because it will stick better and you will have to remove all of the paper tape and replace it with kapton tape. You might also find some pieces of rigid cardboard/paper like material in there, I wrapped those in some kapton tape as well for protection against the heat and inserted them back where they were. Your oven should look something like this when you’re done.
Designing A C5W Cree LED Bulb With Constant Current Driver | Voltlog #333
In a previous video I showed how I designed and assembled my own T10 style LED bulbs for the purpose of installing them in my car for the interior lighting. I was sick of these cheap bulbs I was getting from Aliexpress which didn’t last very long due to poor thermal performance and also they had this nasty blue tint color for the LEDs. The video I’m talking about is Voltlog #319, those bulbs have been installed in my car for the past couple of months, they are great. I love them and I’m pretty sure I will never have to replace those again.
Unfortunately T10 is not the only style of bulb that my VW uses on the interior lights, it also uses this style of bulb which is called C5W festoon for the lights on the sunvisor area. This comes in a few different lengths, I need mine to be 37.5 mm. So you can probably guess what I did next, I took the circuit I used previously and adapted the layout to fit the C5W outline.
PCB Solder Trainer | Voltlog #328
Welcome to a new Voltlog, the title probably gave it away already, this video is about a pcb solder trainer that I designed to measure ones soldering skills. This is not a new idea they have been around for a long time and there have been different designs around but you can join me in this video to see how I designed mine.
I remember how soldering felt back when I was just starting tinkering with electronics, I think I was about 7-8 years old and I had this big communist soldering iron that I got from my father, this was about 100W rated, it had a small flashlight incandescent bulb and it used this thick copper wire as the soldering tip. It was great for soldering big stuff due to the power rating and the ability to transfer that heat efficiently. I remember I was using too much solder, I was making these huge solder blobs.
So back to the board design, let’s take a closer look at what I have in here. On the left we start with 01005 passives, these are 5 resistors in series and at the end of the string there is an LED. The LED has to be bigger because you can’t get them that small so the LED starts at 0402, imperial size. If you get all 5 resistors and the LED soldered right and you apply 5V to this header, the LED should light up and that’s your indication that you’ve at least electrically got everything connected right.
And the size of the components then goes up to 0204, 0402, 0603, 0805, 1203 then we have some resistor networks which I believe are 4×0603. Then we have some SOT23 devices these can be dual diodes also connected in series that will light up an LED.
Depending on the type of LED you choose and it’s forward voltage you can calculate what resistor values you need so the LED will light-up. In general a green LED with 47ohms resistor should work for this and the pads for each of these passive components are the hand solder type which makes them wider so that’s something to help you out.
Fix Microscope Ring Light Reflections With These Projector Lamps | Voltlog #327
You’ve no doubt seen this before on the channel, it’s the trinocular microscope that I have reviewed in Voltlog #282 and I’ve also done a bunch of follow-up videos since then on how to improve the camera system. This comes equipped with an LED ring lamp to illuminate the working surface if you’ve used a setup like this for soldering you’ve no doubt experienced the reflections you get from shiny surface likes the PCB material, especially when you start adding flux into the mix. I’ll overlay some images so you can get a sense of what I’m talking about but basically, since the ring light is shining light right from where the barlow lens is, there are these annoying reflections.
Today I want to show you an alternative lighting system that will help go around that problem. This is a system with individual gooseneck LED lamps. Having this flexible gooseneck tube allows you to position the lamps at an angle that would avoid those nasty reflections.