A circuit is provided for a seed sensor which includes a light source and a light responsive element respectively positioned along a path of travel of seeds for producing a momentary change in signal level from the light responsive element in response to a momentary change of level of light incident thereupon from the light source due to the passage of one or more seeds therebetween. In accordance with the invention, the circuit comprises a pulse-producing circuit responsive to the change in signal level from the light responsive element for producing a discrete pulse signal in response to each change in the direction of the change in signal level. Predetermined ones of the discrete pulse signals are selected for counting.
