Voltlog #294 – InTheMail

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. Before I get started I’m gonna take a second to remind you to subscribe to the channel and hit the bell notification icon because that’s the only way you will know for sure when I upload new videos. 

Depending on which part of the world you live in, you might be dealing with the same isolation measures as I am, the government is recommending we stay inside as much as possible here in Romania, to avoid contact with other people. So that gives me more time to work on projects, learn new stuff and of course discover and order stuff from the internet.

I’m gonna start with this notebook which has a retro looking leather cover, I think it’s quite neat looking, I’m not sure if this is real leather or not, description just said leather. I always keep a notebook around the workbench, it can be useful for drafting a quick schematic, some dimensions or just for writing down some measurements. Another cool feature of this notebook is the binder style clips you have inside, which allow you to insert or remove paper and what’s even nicer is that you can find this type of paper with different grid styles and they’re very affordable.

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 #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 #261 – InTheMail

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time.

Voltlog #78 – 2x25W Bluetooth 4.1 Stereo Amplifier TDA7492P

In this episode we are going to build a bluetooth speaker amplifier based on the TDA7492P class D audio amplifier coupled with a Bluetooth 4 module. We are not actually going to build the amplifier module because we can get that from China, very affordable, it only costs around $12 shipped which is way less that it would cost us to buy the bluetooth module and the TDA7492P individually not to mention the cost of fabricating a PCB of this size.

So we are actually going to use this module and build the final product with a nice enclosure and a suitable external power supply

Here are some links for the parts used to build this project:

Wiring diagram below:

Voltlog #76 – InTheMail

This what happens when I left myself on a shopping spree, you get a month’s worth of InTheMail episodes. So let’s get started on the 4th episode in a row showing the stuff I get from China.

Here is a list with the items shown in this video:

  • Brushless Blower Fan 12V 5015S
  • Brushless Blower Fan 5V 6015S
  • Cooling Fan 5V 2 Pin 50x50x10mm
  • Fan Grill Guard 50mm
  • Aluminium Heatsink 150x60x25mm
  • TO-220 Aluminum Heatsink 34x12x30mm
  • 100W Wire Wound Aluminium Housing Resistor
  • 200x175x70mm Plastic Enclosure For Instrument
  • 170x130x75mm Metal Enclosure For Instrument
  • Rubber Feet Self Adhesive 15mm
  • LM2596 DC-DC Step-Down Converter Module
  • XL6009 Buck-Boost DC-DC Converter
  • 10A BMS 3S Battery Protection Module
  • Zener Diode Assortment – Through Hole
  • Zener Diode Assortment – SMD
  • PT4115 LED Driver IC

Links for all of the items will be in the video description on youtube.