Level indication system for vessel containing liquid has vertical row of LED's each with one terminal projecting into liquid and other terminal connected to positive pole of direct current supply

摘要

The negative terminal (5) of each LED (4) is sealed into the side of the vessel (1) and projects into the interior. The lower sensor electrodes (3) are immersed in the liquid, and a circuit is completed via an electrode (12) at the bottom of the vessel, connected to the negative pole of the direct current supply. The positive terminal (6) of each LED is connected directly to the positive pole of the current supply.