Heating system for aquarium with controlled temperature distribution

摘要

A heating system for an aquarium has an electric immersion heater (5) which is suspended within the tank (8) and also incorporates a second heating element (3) placed along the tank bottom. The latter heater (7) is formed by a length of heating cable energised from a low voltage supply and both heaters (5, 7) are controlled by a mains (1) connected regulator (2). The regulator (2) receives signals from the independent temperature sensors (3, 4) and a pulse width modulated source provides a decreasing temperature gradient of e.g. up to 2 deg. C. between the tank ballast layers (6) and main volume of water over a presettable operating range.