Welcome to a new Voltlog, today we’re going to take a closer look at an ultrasonic cleaner. This is the 1.3 litre, model number I believe is Y-009, the ultrasonic power is 60W while the heating power is rated for 100W. Usable area I’ve measured to be 125x115x40mm depth which is not a lot but I’ve thought about it and this is pretty much all I need. 99% of the PCBs I design fit within these dimensions so it’s not worth getting a bigger ultrasonic cleaner because it will take up more space and it will use up more cleaning liquid, it would be a waste of resources.
Tag: diy
Voltlog #266 – How To Check If Your Raspberry Pi 4 Is Throttling CPU
Welcome to a new Voltlog, today my raspberry pi 4 is again in the spotlight because I want to show you the different scenarios where the board could be throttling down the CPU frequency and how you can identify those. Because it might be a case where your raspberry pi is running slow on a particular task and you don’t know why because there is no built-in mechanism to let you know when the board is throttling down. There are logs which you can check but let’s be honest, few people actually check the logs for something like this.
Throttling of the cpu frequency occurs for good reasons, to protect the board or the cpu from overheating or to prevent any errors from occurring in the case of an under-voltage scenario which may lead to data loss or corruption. Luckily there is a way to check if your system is under one of these conditions, you can run this command on your raspberry pi.
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 #264 – Passive Heatsink Cooling For The Raspberry Pi 4
Welcome to a new Voltlog, here is my raspberry pi 4 which I got a few months ago when they released it and if you have one you might have noticed it gets quite hot especially when it has to do some processing. This newer processor, will get hot quick and the board alone cannot cope with all of this heat so what does it do? Well when the CPU temperature reaches 80 degrees Celsius it will start throttling down the CPU as a way of protecting itself from overheating and this will result in a loss of performance.
The Raspberry Pi 4 has a 1.5GHz quad-core 64-bit Arm Cortex-A72 CPU, that’s roughly three times the performance of the raspberry pi 3 cpu. That inevitably generates more heat. In the original plastic case just sitting idle, connected to a network, doing pretty much nothing, the raspberry pi4 when compared to a raspberry pi3 runs about 12 degrees hotter.
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
Voltlog #260 – How do you test usb to serial converters? (CP2103 vs CH340E vs FT232RL)
Welcome to a new Voltlog, today we’re comparing a few different serial to usb adapters and the discussion started ever since I showed the CH340E breakout board I designed in voltlog #249. People wanted to know if this CH340E affordable chip would perform similar to the well known FTDI or Silicon labs chips, and I’m thinking at high throughput and reliability here, the kind of application where you are sending lots of data, fast and you need it to be transferred reliably.
So today I’m going to compare the CH340E with a CP2103, and the FT232RL. I wasn’t sure what measurements to take and how to test these but I devised 2 testing methods.
Voltlog #258 – Cheaper Isopropyl Alcohol Wipes For PCB and Stencil Cleaning
Welcome to a new Voltlog, today we’ll have a little chat on IPA cleaning wipes. Professional PCB wipes soaked in IPA are pretty expensive and hard to get but can we substitute those with something cheaper that works just as nice for cleaning the flux residue from PCBs?
Voltlog #254 – Epaper Display Pixel vs Segment Type
Welcome to a new voltlog, today we’ll have a little chat on epaper displays. You probably saw this post I made to my youtube community page a few days ago, it was about my epaper thermometer which suddenly showed the low battery sign and stopped working. I’ve only had this running for 1 month, when I received it, the battery was not connected so I thought it must have been an old battery or a bad one.
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.