The 4 photodiodes in parallel allow for greater sensitivity to infrared light then a single detector.
The amplified voltages are minused to produce an error voltage that passes to another difference amplifier thats compared with a potentiometer output voltage to drive the positioning motor.
The motor has a mechanically connected potentiometer to determine the motors position. The motor will rotate to the correct direction to ensure that both X or Y photodiodes have an equal reading, meaning the infrared signal is directly infront of the device.
The circuit requires a dual power supply as well.
