Author: voltlog

Voltlog #86 – Limiting Iphone USB Charging To 500mA

It all started a few days ago when I was talking with a friend and he suggested, since we do most of our phone charging at night, why not charge them at a lower rate for increase battery life. As you may know, when you increase the charging current, charging happens faster at the expense of losing battery life over time, you get fewer battery cycles before it starts losing its capacity.

So I decided to build this small gadget, that goes between the usb output of my charger and the usb plug from my charging cable. In my case I have an Iphone and the charging current can be limited to 500mA by having a set of resistors on the USB data lines.

Links for the parts used to build the project:

Voltlog #85 – STM32 OLED T12 Soldering Station

Today we are taking a look at this soldering station which I got from Taobao (Chinese Ebay). This unit is fully contained, power supply is built-in, it works with T12 Hakko tips and it has a nice 1.3 inch OLED display. It’s powered by the STM32 microcontroller which should make it easy to hack if anyone is interested.

Here are links to the items shown in the video:

Voltlog #83 – InTheMail

Hello, and welcome to a new InTheMail. It’s been awhile since we’ve had one but don’t worry small packages from China continued to arrive, even through the holiday season and as a result I have plenty of new stuff to show on 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:

Voltlog #77 – InTheMail

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

  • USB Drive Spy Camera
  • 35W Radar Motion Sensor Switch
  • 4 Channel Wireless Remote Control Switch
  • 64 LED 20W 2835 Horizontal Led Light
  • 64 LED 60W E27 5730 Light Bulb
  • 21 LED 15W E27 Globe Light Bulb
  • 21 LED 15W E27 Energy Saving Light Bulb

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