The Tach-Rotor Adapter TRA) works with 3-wire 12VDC fans commonly found in computers, computer power supplies, uninterpretable power supplies, DVRs, servers, and other electrical equipment with active cooling systems. Rotor-Locked fans produce a signal on the Sense wire that is in one of two states, FAIL (Locked Rotor) or GOOD (Spinning Rotor). The TRA has two main functions; Tach-to-Rotor Conversion and Speed Sensing and Display.
The TRA converts the tachometer signal from a Tach Fan to a rotor-locked signal thus converting a Tachometer fan into a Rotor-Locked fan. With the TRA, a common computer fan can be converted for use in a rotor-locked application by simply inserting the TRA between the fan and the end-use equipment.
Speed Sensing and Display:
In the same way a computer is able to calculate fan speed, the microcontroller in the TRA calculates fan speed and turns on an RGB LED (red-green-blue) to an pre-programmed color indicating which one of four speed ranges, or bands, the fan is operating.