Design with TIP120 Hi-Current Darlington Transistor in Cirkit DesignerThe TIP120 is a widely used NPN Darlington transistor capable of handling high current loads. It is designed for general-purpose amplifier and low-speed switching applications. The TIP120 is particularly useful for interfacing with microcontrollers, such as the Arduino UNO, to control devices like motors, solenoids, and relays that require more current than a microcontroller can provide directly.
This is a multi-channel LED control system with user input and distance sensing capabilities. An Arduino Nano microcontroller drives TIP120 transistors to switch 12V blue LEDs on and off. The circuit also integrates pushbuttons for manual control and HC-SR04 ultrasonic sensors for triggering LED states based on distance measurements.
Open Project in Cirkit Designer
This circuit uses a 9V battery to power a DC motor, with a TIP120 Darlington transistor acting as a switch. The speed of the motor is controlled by a rotary potentiometer, which adjusts the base current of the transistor.
Open Project in Cirkit Designer
This circuit appears to be a microcontroller-based system with an Arduino UNO at its core, interfacing with various peripherals. It includes a DC motor controlled by a TIP120 Darlington transistor, which is likely PWM-driven from the Arduino for speed control. The circuit also features a temperature sensor (NTC), a real-time clock module (rtc MODULE), a user input interface (4X4 Membrane Matrix Keypad), and an LED indicator with a current-limiting resistor. The purpose of the circuit could be a time-based temperature monitoring and motor control system with user input capabilities.
Open Project in Cirkit Designer
This circuit is designed for controlling high-current devices such as water pumps and LEDs, with signal conditioning provided by an INA125 instrumentation amplifier. It includes switching mechanisms using reed relays and PNP transistors, and is managed by two Arduino UNO microcontrollers, which are currently programmed with placeholder code.
Open Project in Cirkit Designer| Pin Number | Name | Description |
|---|---|---|
| 1 | Base | Control signal input, activates the transistor |
| 2 | Collector | Connected to the high-power load |
| 3 | Emitter | Connected to ground (common reference) |
// Define the pin connected to the base of the TIP120
const int controlPin = 3;
void setup() {
// Set the control pin as an output
pinMode(controlPin, OUTPUT);
}
void loop() {
// Turn on the load connected to the TIP120
digitalWrite(controlPin, HIGH);
delay(1000); // Wait for 1 second
// Turn off the load
digitalWrite(controlPin, LOW);
delay(1000); // Wait for 1 second
}
Q: Can I use the TIP120 to control an AC load? A: No, the TIP120 is designed for DC applications only.
Q: What is the function of the Darlington pair inside the TIP120? A: The Darlington pair configuration within the TIP120 allows for high current gain, enabling control of high-current loads with a very small base current.
Q: How do I choose the correct base resistor value? A: The base resistor value depends on the voltage of the control signal and the desired base current. Use Ohm's law (R = V/I) to calculate the appropriate resistor value, ensuring the base current does not exceed the microcontroller's maximum current rating for a pin.