How to Use TB74/TB74B Bill Acceptor: Examples, Pinouts, and Specs

Introduction

The TB74/TB74B Bill Acceptor is a reliable and efficient electronic component designed for use in vending machines, kiosks, arcade systems, and other automated payment systems. This device is capable of recognizing and validating various denominations of banknotes with high accuracy. It is equipped with advanced sensors and firmware to ensure secure and fast transactions, making it an essential component for cash-handling applications.

Explore Projects Built with TB74/TB74B Bill Acceptor

Use Cirkit Designer to design, explore, and prototype these projects online. Some projects support real-time simulation. Click "Open Project" to start designing instantly!

Raspberry Pi 4B-based Payment Kiosk with Coin and Bill Acceptors

This circuit features a Raspberry Pi 4B as the central controller, interfaced with a variety of peripherals for a payment and display system. It includes a bill acceptor and multi coin acceptor for monetary input, a thermal printer for receipts, and a touch display for user interaction. The circuit also incorporates a 12V to 5V step-down converter to power the 5V components and a membrane matrix keypad for additional input options.

Open Project in Cirkit Designer

Arduino UNO RFID Smart Trolley with I2C LCD Display and Bluetooth Connectivity

This circuit is designed for a smart shopping trolley billing system. It uses an Arduino UNO to interface with an RFID-RC522 reader for scanning items, an I2C LCD screen for displaying information, and pushbuttons for user input to add or remove items from the bill. The system also includes a buzzer for audio feedback, an HC-05 Bluetooth module for wireless communication, and a 9V battery for power supply.

Open Project in Cirkit Designer

Arduino-Based Smart Shopping Trolley with RFID and LCD Display

This circuit is designed for a smart shopping trolley billing system. It includes an Arduino UNO microcontroller interfaced with an RFID-RC522 reader for scanning items, a 16x2 LCD screen with I2C for displaying information, and a buzzer for audio feedback. The system uses pushbuttons to add or remove items from the bill and reset the billing process, with resistors for button debouncing.

Open Project in Cirkit Designer

ESP32-Based Coin and Bill Acceptor with TFT Display and Thermal Printer

This circuit is a vending machine control system that integrates an ESP32 microcontroller to manage various peripherals including a multi-coin acceptor, coin hopper, bill dispenser, money acceptor, thermal printer, and a TFT LCD display. The system is powered by a 12V battery and a buck converter to step down the voltage for the ESP32 and other components, enabling the machine to accept and dispense coins and bills, print receipts, and display information on the screen.

Open Project in Cirkit Designer

Common Applications and Use Cases

• Vending machines for snacks, beverages, and other products
• Parking payment systems
• Arcade and gaming machines
• Ticketing kiosks
• Automated toll collection systems

Technical Specifications

Key Technical Details

Pin Configuration and Descriptions

The TB74/TB74B Bill Acceptor typically uses a 9-pin connector for power and communication. Below is the pinout description:

Usage Instructions

How to Use the Component in a Circuit

1. Power Connection: Connect the VCC pin to a regulated 12V DC power supply and the GND pin to the ground of your circuit.
2. Communication Setup: Choose the desired communication protocol (Pulse, RS232, or MDB) and connect the corresponding pins to your microcontroller or vending machine controller.
3. Enable Bill Acceptance: Use the INHIBIT pin to enable or disable bill acceptance. Pull the pin low (0V) to enable and high (5V) to disable.
4. Banknote Validation: Insert a banknote into the acceptor. The device will validate the note and output a signal (e.g., pulses or RS232 data) corresponding to the denomination.
5. Output Handling: Process the output signal in your controller to register the payment and trigger the appropriate action (e.g., dispensing a product).

Important Considerations and Best Practices

• Ensure the power supply is stable and within the specified voltage range to avoid damage to the device.
• Regularly clean the bill path and sensors to maintain optimal performance and prevent misreads.
• Use proper shielding and grounding to minimize interference in communication lines.
• When using RS232 or MDB protocols, ensure the baud rate and other communication settings match between the bill acceptor and the controller.
• Test the system with various denominations to verify proper validation and output signals.

Example Code for Arduino UNO (Pulse Mode)

Below is an example of how to interface the TB74/TB74B Bill Acceptor with an Arduino UNO using the Pulse mode:

// TB74/TB74B Bill Acceptor - Pulse Mode Example
// Connect the PULSE OUT pin to Arduino digital pin 2
// Connect the INHIBIT pin to Arduino digital pin 3

#define PULSE_PIN 2  // Pin for receiving pulses
#define INHIBIT_PIN 3 // Pin to enable/disable bill acceptance

volatile int pulseCount = 0; // Variable to store pulse count

void setup() {
  pinMode(PULSE_PIN, INPUT_PULLUP); // Set PULSE_PIN as input with pull-up
  pinMode(INHIBIT_PIN, OUTPUT);    // Set INHIBIT_PIN as output
  digitalWrite(INHIBIT_PIN, LOW);  // Enable bill acceptance (LOW = enabled)

  attachInterrupt(digitalPinToInterrupt(PULSE_PIN), countPulse, FALLING);
  Serial.begin(9600); // Initialize serial communication
}

void loop() {
  // Print the pulse count every second
  Serial.print("Pulses received: ");
  Serial.println(pulseCount);
  delay(1000);
}

void countPulse() {
  // Interrupt service routine to count pulses
  pulseCount++;
}

Notes:

• Each pulse corresponds to a specific denomination. Refer to the manufacturer's documentation for the pulse-to-denomination mapping.
• Ensure the INHIBIT_PIN is set to LOW to enable bill acceptance.

Troubleshooting and FAQs

Common Issues and Solutions

1. The bill acceptor does not power on:

   • Verify that the power supply is providing 12V DC and is properly connected to the VCC and GND pins.
   • Check for loose or damaged wires in the power connection.

2. The device does not accept banknotes:

   • Ensure the INHIBIT pin is set to LOW to enable bill acceptance.
   • Clean the bill path and sensors to remove dust or debris.
   • Verify that the banknote is within the supported width range (62mm to 77mm).

3. Incorrect or no output signal:

   • Check the communication protocol settings (Pulse, RS232, or MDB) and ensure they match between the bill acceptor and the controller.
   • Inspect the wiring for loose connections or interference.

4. Frequent misreads or rejections:

   • Clean the sensors and ensure the banknotes are not excessively wrinkled or damaged.
   • Update the firmware if available to improve validation accuracy.

FAQs

• Can the TB74/TB74B accept multiple currencies? Yes, the device can be programmed to recognize multiple currencies, but this requires specific configuration or firmware updates.

• What happens if a counterfeit note is inserted? The bill acceptor will reject counterfeit or invalid notes and return them to the user.

• Is the device compatible with Arduino? Yes, the TB74/TB74B can be interfaced with Arduino using Pulse or RS232 communication protocols.

• How do I clean the bill acceptor? Use a soft, lint-free cloth and a mild cleaning solution to clean the bill path and sensors. Avoid using abrasive materials or liquids that could damage the device.

By following this documentation, you can effectively integrate and maintain the TB74/TB74B Bill Acceptor in your application.