Signal Power Interface (SPI)


Product Overview:

The Signal Power Interface (SPI) plays a crucial role in ensuring the reliable power and operation of PedSafety’s Guardian® product line, WiAAPS® product line, TLPI®, and Audible Beacon Device. It accomplishes this by efficiently converting the standard 120V power source or a 48V power source within the pedestrian signal head into a safe and manageable 12V supply. The SPI’s primary function is to retrieve and transmit the walk and don’t walk information to the connected product, thereby contributing to enhanced pedestrian safety.

About the Product:

The Input connections of our SPI (Signal Power Interface) present a robust and secure solution for pedestrian signal head wiring. These connections include 48 VDC or 89-134 VAC (depending on your SPI) fused and surge-protected inputs for walk, don’t walk, and AC neutral, ensuring reliable operation even in all conditions. On the output side, the SPI offers a straightforward connection to the corresponding terminal block with four wires, including power (+12VDC), – GND, walk, and don’t walk. SPI is designed for easy installation inside various types of pedestrian signal heads, providing a hassle-free setup. It boasts extensive transient protection and is encapsulated in UL94-V0-listed flame-retardant polyurethane, guaranteeing resilience.


Product Information:

Item Description Standard SPI – 120 AC SPI XC – 120 AC SPI – 48 VDC
Part Number 501-0300 501-0301 501-0303

Additional information

Item Description

Standard SPI, SPI 48V (Extra Capacity)

Features and Benefits


  • Can power all PedSafety APS products and TLPI
  • Ensures reliable power and operation
  • Encapsulated in UL94-V0-listed flame retardant-polyurethane
  • Extensive transient protection

Key Benefits:

  • Allows product compatibility with both 120 AC and 48 VDC intersections
  • Designed for easy installation inside various types of ped heads
  • Input connections on SPI are a secure solution for ped head wiring

What's Included?

  • Signal Power Interface
  • Mounting hardware

Features Available for Upgrade:

  • Outdoor Tape

Sales Sheet, Product Sheet, and Manuals

Standard SPI Product Sheet

48V SPI Product Sheet

Standard and XC SPI Sales Sheet

48V SPI Sales Sheet