How to measure the speed of an electric fan conveniently and precisely?
Can be measured with a laser tachometer, affixed with reflective stickers, measured several times, the effect is good
High speed video recording, then slow down. Put your watch on the edge and check for yourself
If you have a variable frequency light, you can gradually increase the frequency until the first fan page is almost stationary, and then multiply by three to calculate the speed
Assemble the light sensor, then calculate the frequency and calculate the speed after the fan number
You open the electric fan of the skull, which has a large gear for swing, count and motor gear ratio, make a mark on the big gear, and then calculate the gear turn to how long you can reverse out a plurality of the fan motor.
