Circuit Documentation

Summary

This circuit is designed to control a 12V PWM fan using an ESP32 microcontroller. The circuit includes a TIP120 Darlington transistor to switch the fan, a 1N4007 rectifier diode for protection, a resistor to limit current, and a Mini 560 step-down converter to provide 5V power to the ESP32. The ESP32 is used to generate PWM signals to control the fan speed.

Component List

1. Resistor

   • Description: 1k Ohm resistor
   • Pins: pin1, pin2
   • Properties:
     • Resistance: 1000 Ohms

2. 1N4007 Rectifier Diode

   • Description: General-purpose rectifier diode
   • Pins: Cathode, Anode

3. TIP120 Hi-Current Darlington Transistor

   • Description: NPN Darlington transistor
   • Pins: BASE, COLLECTOR, EMITTER

4. 12V PWM Fan (120mm)

   • Description: 12V DC fan with PWM control
   • Pins: GND, +12V, TACH, PWM

5. ESP32

   • Description: Microcontroller with Wi-Fi and Bluetooth capabilities
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT

6. 12V Power Supply

   • Description: Provides 12V DC power
   • Pins: +, -

7. Mini 560 Step Down 20-7V to 5V

   • Description: Step-down converter to provide 5V from 12V input
   • Pins: IN-, IN+, OUT-, OUT+

Wiring Details

Resistor

• pin1 is connected to the BASE of the TIP120 Hi-Current Darlington Transistor.
• pin2 is connected to D14 of the ESP32.

1N4007 Rectifier Diode

• Cathode is connected to IN+ of the Mini 560 Step Down 20-7V to 5V, +12V of the 12V PWM Fan (120mm), and + of the 12V Power Supply.
• Anode is connected to GND of the 12V PWM Fan (120mm) and COLLECTOR of the TIP120 Hi-Current Darlington Transistor.

TIP120 Hi-Current Darlington Transistor

• BASE is connected to pin1 of the Resistor.
• COLLECTOR is connected to Anode of the 1N4007 Rectifier Diode.
• EMITTER is connected to IN- of the Mini 560 Step Down 20-7V to 5V and - of the 12V Power Supply.

12V PWM Fan (120mm)

• GND is connected to Anode of the 1N4007 Rectifier Diode.
• +12V is connected to Cathode of the 1N4007 Rectifier Diode.
• PWM is connected to D21 of the ESP32.

ESP32

• D14 is connected to pin2 of the Resistor.
• D21 is connected to PWM of the 12V PWM Fan (120mm).
• GND is connected to OUT- of the Mini 560 Step Down 20-7V to 5V.
• VIN is connected to OUT+ of the Mini 560 Step Down 20-7V to 5V.

12V Power Supply

• + is connected to Cathode of the 1N4007 Rectifier Diode.
• - is connected to EMITTER of the TIP120 Hi-Current Darlington Transistor and IN- of the Mini 560 Step Down 20-7V to 5V.

Mini 560 Step Down 20-7V to 5V

• IN+ is connected to Cathode of the 1N4007 Rectifier Diode.
• IN- is connected to EMITTER of the TIP120 Hi-Current Darlington Transistor and - of the 12V Power Supply.
• OUT- is connected to GND of the ESP32.
• OUT+ is connected to VIN of the ESP32.

Code

No code is provided for this circuit.