Practice / Hardware & Robotics
Switch a 12 V relay from a 3.3 V MCU
Medium · Whiteboard
A 12 V relay coil measures 400 Ω. Switch it from a 3.3 V microcontroller pin. Draw the circuit, choose the parts, and explain what happens if you leave out the diode.
Create a free account to answer it and get scored on what a strong answer covers.