Traffic countdown timers are auxiliary display devices installed next to traffic lights. They use LEDs to display the remaining seconds of the red and green lights in real time, assisting drivers in anticipating traffic conditions. As of 2025, Shenzhen has gathered several manufacturers, including Fama New Intelligent, Mingyi Traffic Technology, and Yeqin Traffic Technology, whose products cover types such as ordinary countdown signs and variable lane control signs.
This device adopts a modular design, features high brightness, and supports red, yellow, and green light displays. Dot-matrix countdown timers can integrate the display of countdown numbers, text, and images, and support three control methods: communication, trigger, and follow. Mainstream general-purpose models have protection ratings from IP54 to IP65, an operating temperature range of -20℃ to 70℃, and a maximum display duration of 99 seconds.
Fieldbus-type traffic countdown timers use a multi-MCU structure. Functional execution is completed by the 89C51, and node communication tasks are completed by the 3150, forming part of the intelligent traffic control system. Its display segments consist of multiple ultra-high brightness LEDs, using a static constant voltage drive method. Brightness adjustment employs a periodic adjustment of the conduction time percentage, with a period of 10ms, and is divided into 10 brightness levels. The design also includes a pen segment detection circuit to detect the pen segment's operational status.
