Tag: Heatsink

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 #259 – InTheMail

Welcome to a new InTheMail, the series that will touch both your passion for electronics and your bank account at the same time. We’re going to start with this small white box, which looks very uninteresting from the outside but contains something really nice, it’s a machined aluminium heatsink, designed specifically for the raspberry pi 4 and inside the box you get the two halves of the heatsink plus some mounting screws and silicone thermal pads.

There is a decent amount of aluminium in this heatsink, and we can see it has these rectangular raised islands for contact with the main chips on the board, so this is where the silicone pads will go. This is a completely passive heatsink and that’s what I was looking for but if you want more cooling power these are also actively cooled heatsink. feel like I should test this in a separate video to see how efficient it is when compared to a no heatsink solution which we already know doesn’t work well with the raspberry pi as it gets pretty hot. So we’ll leave this for a future video.

Voltlog #246 – What if we install a heatsink on the TPS61088 boost module?

In the previous video where I took a closer look at the TPS61088, I did some measurements of the output noise but I also ran the module up to the maximum specified output power of 12V 2A. It was to be expected that the losses would turn into heat and just the small size of the board would not be enough to dissipate all that heat safely so the boost chip reached a toasty 150 degrees Celsius and inevitably went into thermal protection.

There were two questions that people mainly left in the comments of that video. First people were curious if this module would behave differently if a heatsink was installed and also some people thought about using this module in a fixed configuration, because if you remember there is a chip on this module that will switch the output voltage based on quick charge spec, depending on what the load is requesting through that protocol but people might just want a simple fixed output. To this I would add a third question of my own, what is the real efficiency figure of this module, at the maximum output. 

Voltlog #195 – Is Thermal Adhesive Tape Any Good?

Welcome to a new voltlog, today we’re gonna be testing and comparing thermally conductive double sided tape to other solutions like thermally conductive adhesive, silicone pads, or even regular double sided tape to see how effective these solutions are for transferring heat between an IC and the heatsink.

To produce the heat I’m gonna use a small analog electronic load circuit, which will be set for a certain current let’s say 200mA and in theory should produce the same amount of heat for each run. Then we’re going to insert the different type of materials between the heatsink and the IC and we’re gonna measure the temperature of the IC and the temperature of the heatsink. As you can see I have a thermocouple glued to one side of the heatsink with thermally conductive adhesive and another thermocouple glued to this TO247 style transistor that’s producing the heat.

I don’t have a particularly good way of testing this but my plan is to heat the transistor to a stable temperature while the heatsink is kept at room temperature. Then I’m gonna connect the two bodies and measure the time it takes for the heatsink to reach the same temperature or a certain value, close enough. Then repeat the test with a different material and compare the values. If that time span is shorter or longer will depend on the thermal resistance between the body of the transistor and the heatsink and that is highly dependent on the material used between them.

Voltlog #118 – InTheMail

Don’t forget to hit the like button if you enjoyed this video!

Links to all the items shown in this video are below:

Voltlog #103 – InTheMail

Today we are taking a look at my electronics related mail, I’ve got a bunch of random stuff and links for all of them are provided below the video.

Voltlog #82 – DIY Adjustable Analog DC Electronic Load

In this episode I am building an analog adjustable dc load with parts easily obtainable from ebay and banggood. The advantage of such a dc load is that you can understand how it works, modify or repair it if necessary far easier than you would with a digital one. I was able to push mine up to 60W dissipation, but it is recommend to stay under 50W to protect the mosfet.

Here is a list with links to the parts used in this project:

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: