The AN 8248 chip is a driver for a three-phase brushless motor.You can see such a chip on the board of a rotating mirror from a laser printer.Let’s see how this chip works
circuit diagram of the chip connection
The brushless motor contains 12 windings, 4 windings in each phase.The rotor consists of an annular magnet.Hall sensors monitor the position of the rotor
There are 5 pins on the board.The leftmost one is the ground output.The fourth output is a positive power supply.5 output is the output of the signal from the chip to control the speed.A pulse signal for speed control is applied to the 2nd pin and a unit is applied to the 3rd pin to stop the engine
Apply 14 volts of power and tap the 2 pin with your finger.The motor will start to rotate
Apply a pulse signal to pin 2, which is shown in the photo.By changing the pulse width, the motor speed can be adjusted
On the oscilloscope you can see the signal on pin 5
