DC 5V 12V 36V Trigger Counter Module, Accumulator with Memory, 4-Bit 0–9999 Red 0.56-inch Digital Tube Display QF-C04 is a trigger counter module. Each time a trigger signal is input, the counter increments by one. Pressing the Clear button resets the display to zero. Features: 1. Wide input voltage range 2. 4-bit red digital tube display 3. Low-level signal trigger Specifications: 1. Item Name: QF-C04 Trigger Counter Module 2. Model: QF-C04 3. Operating Voltage: DC 4.0V–40V 4. Operating Mode: Trigger mode 5. Trigger Signal: Low-level trigger 6. Display: 0.56-inch, 4-bit red digital tube 7. Operating Temperature: –25°C to +85°C 8. Operating Humidity: 0%–95% RH 9. Dimensions: 65 × 29 × 19 mm Functions: 1. Increments count by one for each valid trigger signal input 2. Resets to zero when the Clear button is pressed Applications: 1. Trigger counting 2. Industrial control systems 3. Equipment monitoring and inspection Note: When using an induction module as the signal source, select an NPN normally open type. When driven by another microcontroller, the low-level signal is the active trigger condition.