Automatically adjusts fan speed based on system temperature using two thresholds: below the accelerated temperature the fans run at the minimum speed, and above the full temperature they run at full speed. This delivers quiet operation during light use and strong cooling under load. Precise temperature setting and control allow reliable management of cooling performance to protect components. The controller only manages the speed of standard fourwire PWM chassis fans and CPU fans, ensuring compatibility with common PC cooling setups. When a monitored fan has an open circuit or stops, the controller triggers an audible and visual alarm (works with a buzzer). The alarm automatically clears when the fan resumes rotation. Clear indicators provide ataglance status of cooling and fault conditions for easy diagnostics. Compact and straightforward integration into typical PC builds without modifying fan wiring or other components. Specifications and compatibility Function: temperaturebased fan speed control for standard fourwire chassis fans and CPU fans Temperature thresholds: accelerated temperature and full temperature govern minimum and fullspeed outputs Alarms: audible (buzzer compatible) and visual alert for opencircuit or stalled fans; automatic clearance on fan recovery Compatibility: standard fourwire PWM chassis fans and CPU fans Size and materials: not specified in the original description Use scenarios Gaming PC or workstation under load: the controller increases fan speed to full when temps exceed the full temperature, ensuring stable performance, while keeping noise low during idle or light tasks by running at minimum speed below the accelerated temperature. Home theater PC or quiet PC builds: during normal use, cooling remains at a low, quiet level; when temps rise, the controller responds to protect components without requiring manual fan adjustments. Test bench or performance tuning: easy oversight of cooling behavior with automatic speed adjustments based on temperature, plus fault monitoring to alert you if a fan stops, helping prevent hardware damage during testing.