Fan Speed Control
Im looking for a fan speed control. Please dont post your internet search results here. Anyone, including me, can do a search and find mindless stuff. I am looking for specific knowledge, thanks ...
Forum Discussion
For reference the 'classic' Fantastic Fan model 4000R draws ~ 3A on high, 2.3A on medium and 1.9A on low. Using a PWM controller, dialed in for what appears/sounds to be about the same speeds medium and low I am seeing 1.6 and 0.9A, so a saving of about 0.7A on medium and 1A on low. I use about 30 - 50Ah a day, so if I were to run the fan overnight on low using my PWM controller, the reduction of ~10Ah would be a noticeable saving.
With a PWM frequency around 20KHz or so there is nor ringing or noticeable increase in noise. There is no output filtering on any of these PWM controllers (the inductance and inertia of the motor takes care of that) and on full on there are no 'conversion losses' when the controller is at full speed. Many of us have been using PWM fan drivers for years, so clearly they and withstand the current spikes from field collapse, maybe they have a fly-back diode across the output.
With a PWM frequency around 20KHz or so there is nor ringing or noticeable increase in noise. There is no output filtering on any of these PWM controllers (the inductance and inertia of the motor takes care of that) and on full on there are no 'conversion losses' when the controller is at full speed. Many of us have been using PWM fan drivers for years, so clearly they and withstand the current spikes from field collapse, maybe they have a fly-back diode across the output.
