Soldering – Page 4

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.

Making Kelvin Test Leads For My LCR Meter | Voltlog #326

A common mistake when building kelvin 4 wire test leads is to use standard alligator clips because in a standard clip the top and bottom jaw are electrically connected at the hinge point. This kinda defeats the purpose of having separate sense lines if they are getting shorted at some point with the current carrying trace. For a true kelvin connection you would need a special type of alligator clip, like the ones shown in this video, these have a plastic hinge and the top and bottom jaws are not electrically connected. These can be quite expensive if they are made by a good manufacturer but I got mine from aliexpress for cheap, they do not excel in quality but good enough for the type of instruments I am going to be using them with and with the amount of work volume they are going to see on my bench they will last a while.

Identifying & Replacing A Fake FTDI FT232R Chip | Voltlog #314

Lately I’ve been getting a few of these serial interfaces from aliexpress, this is just a RS232 to TTL level converter while this one is a USB to RS485 interface and it’s great that we can buy these for cheap for we are getting exactly that, something cheap. This converter chip is likely not of the best quality and not to mention this FT232 chip is certainly not a genuine one.

There is nothing worse than having to deal with communication issues and debugging your tools instead of the actual project you are working on so I’ve decided to replace these chips with some genuine, good parts because the pcb and the rest of the circuit should be fine as long as we have a good conversion chip in there.

You might be wondering if there is any way to tell for sure that you’ve got an FTDI FT232R clone. There are at least 2 methods that I know you can use. First one is to install an older version of the driver which FTDI released in 2014, after plugging your fake FTDI depending on the driver version it will either disable the FT232 chip by writing something to it’s internal EEPROM or it will modify it so that it shows a custom alert message over serial instead of your actual data. I don’t like this method, because there is a better, simpler way, you can simply check for the serial number of the FT232 which you can get from the device manager under windows or by using the FT_Prog utility. If your serial number is A50285BI or 00000000 then you most certainly have a fake chip because that is a popular serial number which is written to fake chips. They don’t bother changing the serial number on the fakes, they mostly write the same number or set it to zero.

8W Rechargeable e-Cig Soldering Iron Review & Teardown | Voltlog #307

These days there is a wide choice of portable soldering iron and I think very few people still consider gas powered soldering irons who were quite popular 10-15 years ago because of their portability.

Now you can get USB powered soldering irons like this one for about $6, it’s rated for 8W, takes a 5V USB input and you can plug this into any power bank and fix a solder joint remotely. I’ve used this a couple of times while doing some electrical work on a car and it was very convenient.

You can also get more powerful, more polished soldering iron like the TS100 which normally takes a DC input from a laptop power brick in the 20V range but since USB Type-C with Power Delivery is a popular thing these days, you can also power it from a power bank capable of at least 12V. But this will be in the $50-60 range and you need to purchase a special power delivery trigger cable separately.

However today’s video is not about these two options, I’m gonna show you something that fits in between these two. It’s delivered rather impressively in a cheap plastic bag but let’s see what we get in here. Looks like they included a small amount of solder wire, that’s nice, every soldering iron should come with a small amount of solder. We get one of these small foldable sheet stands so you won’t burn something when setting the iron on a surface. This looks like our soldering iron tip and inside here we must have the soldering iron body itself and a charging cable

Voltlog #275 – CO2 Concentration Measurement System With MH-Z19B & CCS811

Welcome to a new Voltlog, you might remember these two sensors from a previous mailbag, this is the MH-Z19B and this is the CCS811 both of these report CO2 levels but they measure this differently and I’ll explain this in a moment. I got these two sensors in order to monitor CO2 levels in my home, to determine if the levels rise too much at night, especially during the winter time when we tend to keep the windows closed most of the time. I live in an old apartment building where there isn’t much provision for ventilation and so I suspect the air I breath during sleep is high in CO2 levels as it builds up over night.

In this video I’m gonna show you how I built the monitoring system using an ESP32 board that reads the sensor data and then sends it over the network to an MQTT server running on my raspberry pi. I then use node-red to insert the data into InfluxDB and then finally Grafana to monitor all of this data in a nice graphical user interface. The beauty of this setup is that all of this software is free to use and open-source.

Voltlog #265 – FT232H USB to JTAG/I2C/SPI Interface With Python & PyFtdi

Welcome to a new voltlog, today we’re going to be talking about this little board which I designed and assembled myself, it’s a breakout module for the FTDI FT232H which is a usb to serial converter but with a nice twist. This particular chip from FTDI has the built-in Multi-Protocol Synchronous Serial Engine (MPSSE short) which allows you to run a variety of synchronous serial protocols like JTAG, I2C, SPI or simple bit-banging of IOs. You can imagine it can be really useful to be able to interface with a sensor over I2C or SPI straight from your computer over USB through this interface. You wouldn’t need an arduino or other controller in the middle if you plan to do some data acquisition for example.

Voltlog #262 – Is This The Future of Our Hobby?

To be honest I didn’t think we were going to have services like these available so cheap so fast. I mean yes I know pcb prices have been so low in the past couple of years that it no longer makes sense to etch your own PCBs, unless you are in a big hurry. But having smt assembly service so cheap? Soon enough it would not make sense to hand assemble these boards because it would be equally cheap to have them assembled at JLCPCB