Liquid level over full controller

The utility model relates to a liquid level over full controller which is characterized in that a sensor with n electrodes is installed in a tank, and a resistance is formed between the electrodes and the tank by medium. A voltage divider is formed by the resistance and the resistance of the input end of the corresponding electrode, and the output end of the resistance is connected with a reverser. The output end of the reverser is connected with a light emitting circuit. The number of the branch circuits is n, and a control circuit is in the branch circuit number n minus one. An alarm circuit is in the branch circuit number n. The utility model has the advantages of obvious enhancement of reliability, liquid level display at any time and can give an alarm and automatically cut off power to stop when the liquid is full.