Abstract: A circuit for controlling an automatic ice making system of a refrigeration apparatus. The device includes an electrical circuit which operates the ice making machine using a light interrupter system. A plused light source is placed such that it will be interfered when the ice has reached a predetermined level in the ice containing bin. The circuit uses operational amplifier signal processing components which activate the ice making machine once the light source is sensed for a predetermined period of time and deactivates the ice maker when the light source is not sensed for another predetermined period of time. The circuit also includes means for eliminating the effect of ambient lights.