Abstract
An automatic control circuit of LED street lamp is designed. The circuit is supplied with solar cell and stored electric energy with battery. It has three working modes of light control, delay quenching and delay plus low power. Under the light control mode, the LED street lamp is turned off in daytime and lit at night automatically. Under the delay quenching mode, the LED street lamp is turned off in daytime. It would be lit at night automatically and turned off after the setting time. Under the delay plus low power mode, the LED street lamp is lit at night automatically and changed into pulsed lighting in low power after the setting time. It would be turned off in daytime. The circuit also has the functions of protecting the battery from the over voltage or under voltage and automatic restoration of charging.