Voltlog #273 – 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 reminding 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. Now let’s start with this small esp32 based development board, it has a built-in 1.14 inch color tft lcd and I think that’s a nice feature of this dev board because if you want to connect some sensors and see the readings in real time, you don’t need to wire a display externally it’s built-in.

Another cool feature is that we have built-in battery charging at 500mA and you can power this board through the provided two pin jst connector with a one cell lipo battery which will then charge when connected to power via the USB Type-C port. There is also a CP2104 for the usb to serial conversion and that makes it a pretty well balanced development board for the ESP32.

The board comes loaded with a test program from TTGO, it shows this image then cycles through red, green, blue on the LCD which is a good idea because you can verify the board is functioning ok after the long journey it takes from the market in shenzhen to your door and we all know how well these packages are protected during shipping.

Voltlog #121 – InTheMail

This video starts with a rant about how bad the postal system is around here(Romania).

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

Voltlog #51- InTheMail

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

  • Led 1w amber
  • 3W cool/warm white LED
  • 6W COB LED
  • 16×2 LCD HD44780
  • CREE XPE-R3 LED Mini Penlight Flashlight AAA
  • Green High Power Burning Laser Pointer
  • Green Laser 473nm Protection Glasses
  • HT7333 LDO Regulator
  • 2xAAA Battery holder
  • AAA 1.2V NiMH Rechargeable Battery
  • Terminal Block Connectors
  • 20 Pcs Gold Plated 4mm Banana Plug
  • Silicone Rubber Fan Mounts
  • 16mm Rotary Knobs
  • Neodymium Countersunk Hole Magnets
  • Dental Mirror
  • New T-Handle Tap Wrench Capacity M3-M6

You can find links to all these products in the video description.

Upgrading Workbench Lights Using 7020 White LED Strips

Although the operating temperature of this LED might be up to 85 deg C, while looking through various datasheets, I couldn’t find a graph showing a plot of the expected life in hours vs temperature. If I were to guess I would say you need to run these at less than 50 degrees C to get some decent life out of them. There was a mention of a stress test in a datasheet and that meant for that particular led manufacturer running it at 60 degrees C full rated current for 1000 hours with no resulting damage.

If you have any info on these LED’s and what temperature they should be running at to get some decent life out of them, please leave a comment below.

So to finish up on this story I have to say that I learned some things about these LED strips. If I were to design something from  scratch I would run some basic thermal calculations based on the figures from datasheets but in this case, with these chinese led strips, there is no datasheet, I can’t even easily compare to existing datasheet because these can’t be compared: the driving current is different, the LED only has one die in my case and so on.

The next thing I will try is to double my L shaped heatsink with another piece the same model and size this way I will be increasing my heatsink surface and hopefully cool the LED’s better, maybe shave another 5 degrees.

I will be posting an update with some measurements for comparison once I get the upgrade done. Links for the power supply, led dimmers as well as the light meter used in this video will be in the description of the video so do check them out.