Sanyo Denki provides a wide array of cooling fans, including their 9GA0924P1H01. We’ve had some interesting inquiries lately concerning the PWM frequency for this fan and whether or not users can use a different frequency and if doing so will affect the fan’s service lifetime. Is this the case?
This fan is designed to work with a 25kHz PWM signal, and per the manufacturer using a lower frequency would not affect the lifetime of the fan in any significant way. However, the fan’s performance specifications are liable to shift when using a PWM signal outside of its recommended range, with up to a ten percent swing either direction to be expected. If your signal is low enough, i.e. below 2.5kHz, you may see intermittent performance drops from the fan as the system treats those low signals as ‘PWM off’. In essence, you can use lower signals without affecting the fan’s lifespan, but you’ll have to test your system and adjust it to compensate for the fan’s wobblier performance when run out of spec.