Sensorless BLDC motor can act as generator?

They have some controller chips inside them that switches the coils in specific sequence to rotate the motor. So apparently they can't work as generator. But when I tried blowing in the CPU fan and measured the voltage generated, I could get as much as 1.5V.If I blow harder or rotate it by external means, I could get full 12V?

What puzzles me is since the coils are connected to output ports of the controller chips, how could we use the motor in reverse mode (i.e. generator mode)?

PICMICRO said:

What puzzles me is since the coils are connected to output ports of the controller chips, how could we use the motor in reverse mode (i.e. generator mode)?

Click to expand...

Most likely the ports on the controller chips have protection diodes. (diodes from pins to both power and ground) The protection diodes act like a full wave bridge.

If we line up 1000 teenage girls, all talking into CPU fans, we could power the grid.

ronsimpson said:

If we line up 1000 teenage girls, all talking into CPU fans, we could power the grid.

Click to expand...

You forgot to mention that all of them have to be virgins!

Boncuk

ronsimpson said:

Most likely the ports on the controller chips have protection diodes. (diodes from pins to both power and ground) The protection diodes act like a full wave bridge.

If we line up 1000 teenage girls, all talking into CPU fans, we could power the grid.

Click to expand...

Although it may be possible to generate the wind power by your method, I don't think the protection diodes would be able to transfer power more than a few miliwatts.