Abstract
This is designed to let water tank of water level with automatic control ability. Sensors to collect signal by amplifying circuit after passed to the encoder, produce control circuit signal. When the water beyond set range can automatically adjust the water level in its fall within the scope stipulated by; Water levels low control motor, that tank pumping water level rose when reach a certain height, the motor stops pumping, thus achieved without artificial specifically to control water can make the purpose of keeping within a certain range. Also make cistern display of water level and beyond a certain range of functions. Police
Keywords：Level control； alarm ；display
