13 Control High Voltage Devices скачать в хорошем качестве

13 Control High Voltage Devices

The provided source outlines a technical tutorial for using an ESP32 microcontroller and a TIP120 Darlington transistor to operate a high-voltage solenoid door lock. By acting as an electronically controlled switch, the transistor allows the low-power microcontroller to safely manage devices requiring up to 60 volts. The guide emphasizes essential safety components, such as a resistor to protect the processor pins and a diode to suppress dangerous back EMF voltage spikes caused by the solenoid's coil. To demonstrate the setup, the author implements a password-protected system via the serial monitor, where entering the correct code triggers the lock for five seconds. Finally, the tutorial highlights the importance of a common ground between power sources and previews future integration with Bluetooth technology for smartphone control. The provided video tutorial demonstrates how to use a TIP120 Darlington transistor with an ESP32 microcontroller to control high-voltage devices, specifically a solenoid door lock. Below is a detailed breakdown of the components, wiring, and code logic discussed in the sources: The TIP120 Darlington Transistor The TIP120 is used in this project as an electronic operated switch to bridge the gap between the low-power ESP32 and high-voltage devices (working between 5V and 60V). It features three leads: • Base (Left): Used to control the connection between the other two leads. • Collector (Middle): Connects to the negative lead of the device you are controlling (the solenoid). • Emitter (Right): Connects to the ground (negative lead) of the external power supply. Circuit Wiring and Safety According to the sources, several safety measures are essential to prevent damaging the microcontroller: • Base Resistor: A 1K or 2K Ohm resistor must be placed between the ESP32 GPIO pin (Pin 2) and the transistor's base to protect the pin from the high-voltage supply. • Flyback Diode: A diode is placed across the solenoid to protect the circuit from back EMF. When the solenoid's coil is turned off, it generates a voltage spike that can damage the TIP120; the diode dissipates this energy. The negative lead (indicated by a line) must connect to the positive power supply. • Common Ground: You must connect the GND of the ESP32 to the GND of the external power supply to ensure the circuit works correctly. Software Logic and Control The video explains how to control the lock via the Serial Monitor using a password-based system. • The Setup: The ESP32 defines GPIO Pin 2 as the "base pin" and sets it as an OUTPUT. The Serial communication is initialized at a baud rate of 115200. • The Loop: The code constantly checks if data is available in the Serial Monitor. It reads the incoming string and compares it to a predefined password, such as "0123". • Operation: If the correct password is entered, the ESP32 writes the base pin HIGH, which opens the solenoid for five seconds (5000 milliseconds) before writing it LOW to close it again. Summary of Steps 1. Hardware Assembly: Connect the TIP120, resistor, and diode according to the pinout. 2. Power: Connect a 12V external power supply to the solenoid, ensuring the grounds are shared with the ESP32. 3. Code Upload: Set the password and upload the sketch to the ESP32. 4. Verification: Enter the password into the Serial Monitor (with the "no line ending" option selected) to trigger the lock. To understand how the TIP120 works in this circuit, think of it as a water faucet. The ESP32 is like your hand on the handle (the Base); when you provide a small amount of effort (a low-voltage signal), you allow a much larger flow of water (high-voltage current) to pass from the supply to the drain (the solenoid), turning it on or off. Describe the function of the three TIP120 Darlington transistor leads. Explain the purpose of adding a diode to the circuit. How is the ESP32 ground connected to the external power?