Centralised household water mixer for several outlets - contains IC assembly for each outlet controlling time of water flows to achieve required temperature

摘要

A small central control unit has pipes running from it to various water outlets in a household. These pipes have an outer sheath under which are four different conductors to permit exchange of information between the outlet and control unit. These conductors are not required where only cold water flow is used. The control unit contains control circuits for each outlet where a potentiometer (P) is connected to a handle at the outlet to provide temperature information. This is applied as a voltage to an integrated circuit (IC1) which provides a binary output to switch transistors (T1,T2) for time intervals corresponding to the required water temperature. These transistors control cold (EF) and hot (EC) water flow valves respectively to obtain the required temperature.