Improvements of Flashing mode by programmed control for multiple colors in LED optical stimulus system

Behavior observation examination of Japanese flying squid against optical stimulus is scheduled. A LED optical resource system has been designed as an optical stimulus for this examination. Two kinds of a LED driver and panel system were developed. One consists of constant current power supply units. The other is a LED driver based on Pulse Width Modulation (PWM). About the former, a control and monitor program via a personal computer (PC) was developed. In this paper, the former was described in detail. By control of two parameters of preset current and voltage to a constant current power supply unit, a waveform of LED current was improved. Leading-up time is shorter than nominal value. Overshoot was improved in comparison with a MOSFET switch control. Flashing worked in LED current higher than rated current value.