System for controlling automobile cooling fan

摘要

A system for controlling an automobile cooling fan utilizes a temperature-sensitive negative resistance device having a resistance which decreases as the temperature rises, and which increases as the temperature falls. Thus, if the cooling water temperature does not exceed a certain level, the cooling fan motor is not driven. If the temperature exceeds a certain level, the cooling fan motor is driven in proportion with the dynamic temperature variations. Therefore, a variable cooling fan speed is possible, and therefore, the cooling operation becomes efficient.