Simple power supply based on 18650 lithium battery

The actual adjustable power supply is shown in the picture above and has the following functions:

1. A large SMD LED pad (the spacing is a bit large, the 0603 LED is difficult to detect, it can be made smaller)

And a 2*4 in-line female header, used to measure whether the in-line LED and SMD LED are normal and color,

2. A knob potentiometer, due to adjust the VCC voltage

3. A voltage measuring digital tube display module that displays the VCC voltage, and a yellow short-circuit cap on the right side.

Under special circumstances, it can also be used to measure external voltages

4. Four power outputs, each with independent switch control and LED indication, corresponding to each output voltage

The maximum current parameters are as follows (based on memory and estimation, please refer to the power chip data manual and circuit for details):

                     3.3V 300mA

                     4.2V 2A (battery voltage, may be between 3.6~4.2V)

                     5V 500mA

         VCC 5~15.7V 1A (not recommended to exceed 500mA)

In order to facilitate the search for those who need it, I will introduce the power chip used in this circuit.

The 3.3V voltage regulator chip uses the ME6212C33M5G model. This chip is used by many people and has good results.

The 5V voltage regulator chip uses the AMS1117-5.0 model, which is also a relatively common model.

The DC-DC part uses the SX1308 chip, which is used by some boost modules on a certain product.

Finally, to summarize:

This power supply still has many shortcomings, such as the charging circuit is not perfect and there is no lithium battery power indicator.

Automatic wiring, the schematic may look a bit messy, etc. When I have time, I will make another one and share it with everyone.