Photo Diode Sensors requires power and ground to light the diodes. When the diode's light is passing through a slot, the sensor sees the light and generates a voltage that allows the IC to modulate the input voltage up and down. The output from this sensor is similar to the Hall effect, an up and down voltage from 0 to 5 volts, which corresponds to engine speed for the outside slots or cylinder firing order for the inside slots. It conducts charge at a rate proportional to the intensity of light received by the sensors.

Photo diode sensor requires power and ground to light the diodes. When the diode's light is passing through a slot, the sensor sees the light and generates a voltage that allows the IC to modulate the input voltage up and down. The output from this sensor is similar to the Hall effect, an up and down voltage from 0 to 5 volts, which corresponds to engine speed for the outside slots or cylinder firing order for the inside slots. It conducts charge at a rate proportional to the intensity of light received by the sensors.