[Course Design] Quick power supply for 45MM wide breadboard

Introduction

Quick power supply for 45MM wide breadboard (SYB-130)

Power supply: 6-30V

Optional DC, MicroUSB input interface

Battery powered (any battery of suitable voltage)

Output:

Onboard output interface 5V, 3.3V, 1.25V

Breadboard interface, output jumper optional 5V/3.3V

Breadboard diagram suitable for use

Circuit details

DC and usb interface.

Use 7805 three-terminal voltage regulator to get 5V voltage, and LM317 to get 1.25V voltage

Onboard output power and indicator lights

The non-inverting input of the LM358 op amp is connected to 1.25v, the inverting input obtains output feedback through resistor voltage division, and then the output pin is adjusted to control the conduction degree of Q2 and Q3.

Revise

PS1: Added a few 100nf ceramic capacitors to increase the number of components to 30.

PS2: I was mistaken about the LM337 chip that outputs 1.25v, but it has been corrected to LM317.

PS3: Due to the voltage drop of the chip, the initially envisioned 5v and 4.2v power supplies could not reach the expected output voltage, so the unified power supply was changed to 6-30v.